feat: P2.3 Folder Sharing + P2.5 Email Import + P2.6 Contact Import + P2.7 Free/Busy

- P2.3: Folder sharing system — ShareFolderDialog, sharing-store, sharing-settings
- P2.5: Email import (.eml, .tgz, .zip) with dedup and progress
- P2.6: Contact import (vCard + CSV) with auto-mapping
- P2.7: Free/Busy view grid with color-coded slots

app/(main)/[locale]/settings/page.tsx

@@ -35,6 +35,8 @@ import {
   SwatchBook,
   Download,
   Sparkles,
+  Upload,
+  Share2,
   X,
   type LucideIcon,
 } from 'lucide-react';
@@ -71,6 +73,8 @@ import { PluginsSettings } from '@/components/settings/plugins-settings';
 import { AiAssistantSettings } from '@/components/settings/ai-assistant-settings';
 import { PluginIframeSlot } from '@/components/plugins/plugin-iframe-slot';
 import { offersForSlot as pluginOffersForSlot, subscribe as pluginRegistrySubscribe, get as getActivePlugin } from '@/lib/plugin-sandbox/registry';
+import { ImportSettings } from '@/components/settings/import-settings';
+import { SharingSettings } from '@/components/settings/sharing-settings';
 import { ProtocolHandlerSettings } from '@/components/settings/protocol-handler-settings';
 import { useAuthStore, redirectToLogin } from '@/stores/auth-store';
 import { useEmailStore } from '@/stores/email-store';
@@ -115,6 +119,8 @@ type Tab =
   | 'about_data'
   | 'themes'
   | 'plugins'
+  | 'import'
+  | 'sharing'
   | 'ai_assistant'
   | 'debug';
 
@@ -159,6 +165,8 @@ const tabIcons: Record<Tab, LucideIcon> = {
   about_data: Info,
   themes: SwatchBook,
   plugins: Puzzle,
+  import: Upload,
+  sharing: Share2,
   ai_assistant: Sparkles,
   debug: Bug,
 };
@@ -243,6 +251,8 @@ const tabSearchPaths: Record<Tab, string[]> = {
   themes: [],
   plugins: [],
   ai_assistant: [],
+  import: ['settings.importer'],
+  sharing: ['sharing'],
   debug: ['settings.advanced'],
 };
 
@@ -275,6 +285,8 @@ const tabKeywords: Record<Tab, string> = {
   themes: 'custom theme css skin appearance',
   plugins: 'extensions addons',
   ai_assistant: 'assistant ask model llm ollama chatbot',
+  import: 'import email eml zip tgz mbox csv vcard contacts',
+  sharing: 'share shared folder calendar address book permission',
   debug: 'logs developer console diagnostic',
 };
 
@@ -624,6 +636,7 @@ export default function SettingsPage() {
     { id: 'account', label: t('tabs.account'), icon: tabIcons.account, group: 'general' },
     { id: 'language', label: t('tabs.language'), icon: tabIcons.language, group: 'general' },
     { id: 'notifications', label: t('tabs.notifications'), icon: tabIcons.notifications, group: 'general' },
+    { id: 'sharing', label: t('tabs.sharing'), icon: tabIcons.sharing, group: 'general' },
     { id: 'protocol_handlers', label: t('tabs.protocol_handlers'), icon: tabIcons.protocol_handlers, group: 'general' },
 
     // Appearance
@@ -641,6 +654,7 @@ export default function SettingsPage() {
     ...(supportsSieve ? [{ id: 'filters' as Tab, label: t('tabs.filters'), icon: tabIcons.filters, group: 'mail' as TabGroup }] : []),
     ...(isFeatureEnabled('templatesEnabled') ? [{ id: 'templates' as Tab, label: t('tabs.templates'), icon: tabIcons.templates, group: 'mail' as TabGroup }] : []),
     { id: 'folders', label: t('tabs.folders'), icon: tabIcons.folders, group: 'mail' },
+    { id: 'import', label: t('tabs.import'), icon: tabIcons.import, group: 'mail' },
     ...(isFeatureEnabled('customKeywordsEnabled') ? [{ id: 'keywords' as Tab, label: t('tabs.keywords'), icon: tabIcons.keywords, group: 'mail' as TabGroup }] : []),
 
     // Privacy & Security
@@ -772,6 +786,8 @@ export default function SettingsPage() {
       {effectiveActiveTab === 'filters' && <FilterSettings />}
       {effectiveActiveTab === 'templates' && <TemplateSettings />}
       {effectiveActiveTab === 'folders' && <FolderSettings />}
+      {effectiveActiveTab === 'import' && <ImportSettings />}
+      {effectiveActiveTab === 'sharing' && <SharingSettings />}
       {effectiveActiveTab === 'keywords' && <KeywordSettings />}
       {effectiveActiveTab === 'security' && <AccountSecuritySettings />}
       {effectiveActiveTab === 'content_senders' && <ContentSendersSettings />}

app/api/sharing/route.ts

@@ -0,0 +1,361 @@
+import type { NextRequest } from "next/server";
+
+type JmapMethodCall = [string, Record<string, unknown>, string];
+
+async function jmapRequest(
+  serverUrl: string,
+  authHeader: string,
+  methodCalls: JmapMethodCall[],
+  using?: string[],
+) {
+  const sessionResp = await fetch(`${serverUrl}/.well-known/jmap`, {
+    headers: { Authorization: authHeader },
+  });
+  if (!sessionResp.ok) {
+    return { error: `Session fetch failed: ${sessionResp.status}` };
+  }
+  const session = await sessionResp.json();
+  const apiUrl = session.apiUrl;
+  if (!apiUrl) {
+    return { error: "No API URL in JMAP session" };
+  }
+
+  const body = {
+    using: using || [
+      "urn:ietf:params:jmap:core",
+      "urn:ietf:params:jmap:mail",
+      "urn:ietf:params:jmap:principals",
+    ],
+    methodCalls,
+  };
+
+  const resp = await fetch(apiUrl, {
+    method: "POST",
+    headers: {
+      "Content-Type": "application/json",
+      Authorization: authHeader,
+    },
+    body: JSON.stringify(body),
+  });
+
+  if (!resp.ok) {
+    return { error: `JMAP request failed: ${resp.status}` };
+  }
+
+  return await resp.json();
+}
+
+export async function GET(request: NextRequest) {
+  const { searchParams } = new URL(request.url);
+  const action = searchParams.get("action");
+  const serverUrl = request.headers.get("X-JMAP-Server-Url");
+  const authHeader = request.headers.get("Authorization");
+
+  if (!serverUrl || !authHeader) {
+    return Response.json(
+      { error: "Missing server URL or auth header" },
+      { status: 400 },
+    );
+  }
+
+  if (action !== "principals") {
+    return Response.json(
+      { error: "Invalid action" },
+      { status: 400 },
+    );
+  }
+
+  const result = await jmapRequest(serverUrl, authHeader, [
+    ["Principal/query", { accountId: "" }, "0"],
+    ["Principal/get", {
+      accountId: "",
+      "#ids": {
+        resultOf: "0",
+        name: "Principal/query",
+        path: "/ids",
+      },
+    }, "1"],
+  ]);
+
+  if ("error" in result) {
+    return Response.json(result, { status: 502 });
+  }
+
+  const getResp = (result as Record<string, unknown>).methodResponses as Array<[string, Record<string, unknown>, string]> | undefined;
+  const principals = getResp?.find((r) => r[0] === "Principal/get")?.[1]
+    ?.list ?? [];
+
+  return Response.json({ principals });
+}
+
+export async function POST(request: NextRequest) {
+  const serverUrl = request.headers.get("X-JMAP-Server-Url");
+  const authHeader = request.headers.get("Authorization");
+
+  if (!serverUrl || !authHeader) {
+    return Response.json(
+      { error: "Missing server URL or auth header" },
+      { status: 400 },
+    );
+  }
+
+  let body: Record<string, unknown>;
+  try {
+    body = await request.json();
+  } catch {
+    return Response.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const { kind, resourceId, principalId, role } = body;
+
+  if (!kind || !resourceId || !principalId) {
+    return Response.json(
+      { error: "Missing required fields: kind, resourceId, principalId" },
+      { status: 400 },
+    );
+  }
+
+  let method: string;
+  let shareProperty: string;
+
+  switch (kind) {
+    case "mailbox":
+      method = "Mailbox/set";
+      shareProperty = "shareWith";
+      break;
+    case "calendar":
+      method = "Calendar/set";
+      shareProperty = "shareWith";
+      break;
+    case "addressBook":
+      method = "AddressBook/set";
+      shareProperty = "shareWith";
+      break;
+    case "file":
+      method = "FileNode/set";
+      shareProperty = "shareWith";
+      break;
+    default:
+      return Response.json(
+        { error: `Invalid kind: ${kind}` },
+        { status: 400 },
+      );
+  }
+
+  const patchValue = role === null ? null : buildRights(kind as string, role as string);
+
+  const methodCalls: JmapMethodCall[] = [
+    [
+      method,
+      {
+        accountId: "",
+        update: {
+          [resourceId as string]: {
+            [`${shareProperty}/${principalId}`]: patchValue,
+          },
+        },
+      },
+      "0",
+    ],
+  ];
+
+  const result = await jmapRequest(
+    serverUrl,
+    authHeader,
+    methodCalls,
+  );
+
+  if ("error" in result) {
+    return Response.json(result, { status: 502 });
+  }
+
+  const responses = (result as Record<string, unknown>).methodResponses as Array<[string, Record<string, unknown>, string]> | undefined;
+  const setResult = responses?.[0]?.[1];
+
+  if (
+    setResult &&
+    typeof setResult === "object" &&
+    "notUpdated" in setResult &&
+    setResult.notUpdated &&
+    typeof setResult.notUpdated === "object" &&
+    (resourceId as string) in setResult.notUpdated
+  ) {
+    const err = (setResult.notUpdated as Record<string, Record<string, unknown>>)[resourceId as string];
+    return Response.json(
+      { error: err.description || "Failed to update share" },
+      { status: 400 },
+    );
+  }
+
+  return Response.json({ ok: true });
+}
+
+function buildRights(
+  kind: string,
+  role: string,
+): Record<string, boolean> | null {
+  if (role === null) return null;
+
+  switch (kind) {
+    case "mailbox":
+      return mailboxRights(role);
+    case "calendar":
+      return calendarRights(role);
+    case "addressBook":
+      return addressBookRights(role);
+    case "file":
+      return fileRights(role);
+    default:
+      return readRights();
+  }
+}
+
+function mailboxRights(role: string): Record<string, boolean> {
+  switch (role) {
+    case "read":
+      return {
+        mayReadItems: true,
+        mayAddItems: false,
+        mayRemoveItems: false,
+        maySetSeen: false,
+        maySetKeywords: false,
+        mayCreateChild: false,
+        mayRename: false,
+        mayDelete: false,
+        maySubmit: false,
+      };
+    case "readWrite":
+      return {
+        mayReadItems: true,
+        mayAddItems: true,
+        mayRemoveItems: false,
+        maySetSeen: true,
+        maySetKeywords: true,
+        mayCreateChild: false,
+        mayRename: false,
+        mayDelete: false,
+        maySubmit: true,
+      };
+    case "manager":
+      return {
+        mayReadItems: true,
+        mayAddItems: true,
+        mayRemoveItems: true,
+        maySetSeen: true,
+        maySetKeywords: true,
+        mayCreateChild: true,
+        mayRename: true,
+        mayDelete: true,
+        maySubmit: true,
+        mayShare: true,
+      };
+    default:
+      return mailboxRights("read");
+  }
+}
+
+function calendarRights(role: string): Record<string, boolean> {
+  switch (role) {
+    case "read":
+      return {
+        mayReadFreeBusy: true,
+        mayReadItems: true,
+        mayWriteAll: false,
+        mayWriteOwn: false,
+        mayUpdatePrivate: false,
+        mayRSVP: false,
+        mayShare: false,
+        mayDelete: false,
+      };
+    case "readWrite":
+      return {
+        mayReadFreeBusy: true,
+        mayReadItems: true,
+        mayWriteAll: true,
+        mayWriteOwn: true,
+        mayUpdatePrivate: true,
+        mayRSVP: true,
+        mayShare: false,
+        mayDelete: false,
+      };
+    case "manager":
+      return {
+        mayReadFreeBusy: true,
+        mayReadItems: true,
+        mayWriteAll: true,
+        mayWriteOwn: true,
+        mayUpdatePrivate: true,
+        mayRSVP: true,
+        mayShare: true,
+        mayDelete: true,
+      };
+    default:
+      return calendarRights("read");
+  }
+}
+
+function addressBookRights(role: string): Record<string, boolean> {
+  switch (role) {
+    case "read":
+      return {
+        mayRead: true,
+        mayWrite: false,
+        mayShare: false,
+        mayDelete: false,
+      };
+    case "readWrite":
+      return {
+        mayRead: true,
+        mayWrite: true,
+        mayShare: false,
+        mayDelete: false,
+      };
+    case "manager":
+      return {
+        mayRead: true,
+        mayWrite: true,
+        mayShare: true,
+        mayDelete: true,
+      };
+    default:
+      return addressBookRights("read");
+  }
+}
+
+function fileRights(role: string): Record<string, boolean> {
+  switch (role) {
+    case "read":
+      return {
+        mayRead: true,
+        mayAddChildren: false,
+        mayRename: false,
+        mayDelete: false,
+        mayModifyContent: false,
+        mayShare: false,
+      };
+    case "readWrite":
+      return {
+        mayRead: true,
+        mayAddChildren: true,
+        mayRename: true,
+        mayDelete: true,
+        mayModifyContent: true,
+        mayShare: false,
+      };
+    case "manager":
+      return {
+        mayRead: true,
+        mayAddChildren: true,
+        mayRename: true,
+        mayDelete: true,
+        mayModifyContent: true,
+        mayShare: true,
+      };
+    default:
+      return fileRights("read");
+  }
+}
+
+function readRights(): Record<string, boolean> {
+  return { mayRead: true };
+}

components/calendar/event-modal.tsx

@@ -4,13 +4,14 @@ import { useState, useEffect, useCallback, useRef, useMemo } from "react";
 import { useTranslations, useLocale } from "next-intl";
 import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
-import { X, Trash2, Check, Users, CalendarDays, Copy, Pencil, Clock, MapPin, Video, Repeat, Bell, AlignLeft, Plus } from "lucide-react";
+import { X, Trash2, Check, Users, CalendarDays, Copy, Pencil, Clock, MapPin, Video, Repeat, Bell, AlignLeft, Plus, Eye, EyeOff } from "lucide-react";
 import { format, parseISO, addHours, addDays, isSameDay } from "date-fns";
 import type { CalendarEvent, Calendar, CalendarParticipant, CalendarEventAlert, CalendarRecurrenceRule } from "@/lib/jmap/types";
 import { RecurrenceEditor, buildRecurrenceSummary, isSimpleRecurrenceRule } from "./recurrence-editor";
 import { parseDuration, getEventColor } from "./event-card";
 import { buildAllDayDuration, getEventDisplayEndDate, getEventEndDate, getEventStartDate, getPrimaryCalendarId } from "@/lib/calendar-utils";
 import { ParticipantInput, type ParticipantInputHandle } from "./participant-input";
+import { FreeBusyView } from "./free-busy-view";
 import {
   isOrganizer,
   getUserParticipantId,
@@ -351,6 +352,7 @@ export function EventModal({
       .map(p => ({ name: p.name, email: p.email }));
   });
   const [sendInvitations, setSendInvitations] = useState(true);
+  const [showFreeBusy, setShowFreeBusy] = useState(false);
   const participantInputRef = useRef<ParticipantInputHandle>(null);
 
   // Plugin transform: collect conflict warnings for the current event form.
@@ -1074,6 +1076,44 @@ export function EventModal({
               onAdd={handleAddAttendee}
               onRemove={handleRemoveAttendee}
             />
+            {attendees.length > 0 && !allDay && (
+              <div className="mt-2">
+                <Button
+                  variant="outline"
+                  size="sm"
+                  onClick={() => setShowFreeBusy((prev) => !prev)}
+                  className="text-xs"
+                >
+                  {showFreeBusy ? (
+                    <EyeOff className="w-3.5 h-3.5 me-1" />
+                  ) : (
+                    <Eye className="w-3.5 h-3.5 me-1" />
+                  )}
+                  {showFreeBusy ? t("freeBusy.hide") : t("freeBusy.check")}
+                </Button>
+                {showFreeBusy && (
+                  <div className="mt-3">
+                    <FreeBusyView
+                      participants={attendees}
+                      startDate={(() => {
+                        const d = new Date(`${startDate}T${startTime}:00`);
+                        return isNaN(d.getTime()) ? new Date() : d;
+                      })()}
+                      endDate={(() => {
+                        const d = new Date(`${endDate}T${endTime}:00`);
+                        return isNaN(d.getTime()) ? addHours(new Date(`${startDate}T${startTime}:00`), 8) : d;
+                      })()}
+                      onTimeSelect={(start, end) => {
+                        setStartDate(formatDateInput(start));
+                        setStartTime(formatTimeInput(start));
+                        setEndDate(formatDateInput(end));
+                        setEndTime(formatTimeInput(end));
+                      }}
+                    />
+                  </div>
+                )}
+              </div>
+            )}
             {isEdit && statusCounts && (existingParticipants.length > 0) && (
               <p className="text-xs text-muted-foreground mt-1.5">
                 {t("participants.status_summary", {

components/calendar/free-busy-view.tsx

@@ -0,0 +1,296 @@
+"use client";
+
+import { useState, useEffect, useMemo, useCallback } from "react";
+import { useTranslations } from "next-intl";
+import { addMinutes, differenceInMinutes, format } from "date-fns";
+import { Avatar } from "@/components/ui/avatar";
+import { useAuthStore } from "@/stores/auth-store";
+import { cn } from "@/lib/utils";
+import { fetchFreeBusy, type FreeBusySlot, isWorkingHour as isWorkingHourFn } from "@/lib/calendar-freebusy";
+
+export interface FreeBusyViewProps {
+  participants: { name?: string; email: string }[];
+  startDate: Date;
+  endDate: Date;
+  onTimeSelect?: (start: Date, end: Date) => void;
+}
+
+const SLOT_MINUTES = 30;
+const WORK_START_HOUR = 8;
+const WORK_END_HOUR = 18;
+
+const statusColors: Record<FreeBusySlot["status"], string> = {
+  free: "bg-emerald-100 dark:bg-emerald-900/40 border-emerald-200 dark:border-emerald-800",
+  busy: "bg-red-100 dark:bg-red-900/40 border-red-200 dark:border-red-800",
+  tentative: "bg-amber-100 dark:bg-amber-900/40 border-amber-200 dark:border-amber-800",
+  unavailable: "bg-purple-100 dark:bg-purple-900/40 border-purple-200 dark:border-purple-800",
+  unknown: "bg-muted border-muted-foreground/20",
+};
+
+const statusHoverColors: Record<FreeBusySlot["status"], string> = {
+  free: "hover:bg-emerald-200 dark:hover:bg-emerald-800/60",
+  busy: "hover:bg-red-200 dark:hover:bg-red-800/60",
+  tentative: "hover:bg-amber-200 dark:hover:bg-amber-800/60",
+  unavailable: "hover:bg-purple-200 dark:hover:bg-purple-800/60",
+  unknown: "hover:bg-muted-foreground/20",
+};
+
+function clampToSlot(d: Date): Date {
+  const clone = new Date(d);
+  clone.setSeconds(0, 0);
+  const mins = clone.getMinutes();
+  const remainder = mins % SLOT_MINUTES;
+  if (remainder !== 0) {
+    clone.setMinutes(mins - remainder, 0, 0);
+  }
+  return clone;
+}
+
+function buildHourSlots(start: Date, end: Date): { label: string; slots: FreeBusySlot[] }[] {
+  const hours: { label: string; slots: FreeBusySlot[] }[] = [];
+  let cursor = clampToSlot(start);
+  while (cursor < end) {
+    const hourEnd = new Date(cursor);
+    hourEnd.setHours(hourEnd.getHours() + 1, 0, 0, 0);
+    const hourSlots: FreeBusySlot[] = [];
+    let slotCursor = new Date(cursor);
+    while (slotCursor < hourEnd && slotCursor < end) {
+      const slotEnd = addMinutes(slotCursor, SLOT_MINUTES);
+      hourSlots.push({
+        start: new Date(slotCursor),
+        end: slotEnd > end ? new Date(end) : slotEnd,
+        status: "unknown",
+      });
+      slotCursor = slotEnd;
+    }
+    hours.push({ label: format(cursor, "HH:mm"), slots: hourSlots });
+    cursor = hourEnd;
+  }
+  return hours;
+}
+
+function isWorkingHour(hour: number): boolean {
+  return isWorkingHourFn(hour, WORK_START_HOUR, WORK_END_HOUR);
+}
+
+export function FreeBusyView({
+  participants,
+  startDate,
+  endDate,
+  onTimeSelect,
+}: FreeBusyViewProps) {
+  const t = useTranslations("calendar");
+  const client = useAuthStore((s) => s.client);
+  const [freeBusyData, setFreeBusyData] = useState<Map<string, FreeBusySlot[]> | null>(null);
+  const [loading, setLoading] = useState(false);
+  const [hoveredSlot, setHoveredSlot] = useState<{
+    participant: string;
+    slotIndex: number;
+  } | null>(null);
+
+  const hourSlots = useMemo(() => buildHourSlots(startDate, endDate), [startDate, endDate]);
+  const totalHalfHourSlots = useMemo(() => {
+    let c = 0;
+    for (const h of hourSlots) c += h.slots.length;
+    return c;
+  }, [hourSlots]);
+
+  const now = new Date();
+  const showNowLine =
+    now >= startDate && now <= endDate;
+  const nowPositionPercent = showNowLine
+    ? Math.max(0, Math.min(100, (differenceInMinutes(now, startDate) / differenceInMinutes(endDate, startDate)) * 100))
+    : null;
+
+  useEffect(() => {
+    if (!client || participants.length === 0) return;
+    let cancelled = false;
+    setLoading(true);
+    fetchFreeBusy(client, participants, startDate, endDate)
+      .then((data) => {
+        if (!cancelled) {
+          setFreeBusyData(data);
+          setLoading(false);
+        }
+      })
+      .catch(() => {
+        if (!cancelled) setLoading(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, [client, participants, startDate, endDate]);
+
+  const handleSlotClick = useCallback(
+    (slot: FreeBusySlot) => {
+      if (slot.status === "free" && onTimeSelect) {
+        onTimeSelect(new Date(slot.start), new Date(slot.end));
+      }
+    },
+    [onTimeSelect]
+  );
+
+  const timezone = useMemo(
+    () => Intl.DateTimeFormat().resolvedOptions().timeZone,
+    []
+  );
+
+  if (participants.length === 0) {
+    return (
+      <p className="text-sm text-muted-foreground py-4 text-center">
+        {t("freeBusy.no_participants")}
+      </p>
+    );
+  }
+
+  return (
+    <div className="flex flex-col gap-2">
+      <div className="flex items-center justify-between">
+        <div className="text-xs text-muted-foreground">
+          {t("freeBusy.timezone")}: {timezone}
+        </div>
+        {loading && (
+          <div className="text-xs text-muted-foreground animate-pulse">
+            {t("freeBusy.loading")}
+          </div>
+        )}
+      </div>
+
+      <div className="overflow-auto border border-border rounded-lg">
+        <div className="min-w-max" style={{ minWidth: totalHalfHourSlots * 24 + 200 }}>
+          <table className="w-full border-collapse text-xs">
+            <thead>
+              <tr>
+                <th className="sticky left-0 z-10 bg-background border-b border-r border-border px-3 py-2 text-left w-[180px] min-w-[180px]">
+                  {t("participants.title")}
+                </th>
+                {hourSlots.map((hour, i) => (
+                  <th
+                    key={i}
+                    colSpan={hour.slots.length}
+                    className={cn(
+                      "border-b border-r border-border px-1 py-2 text-center font-medium",
+                      isWorkingHour(new Date(hour.slots[0]?.start).getHours())
+                        ? "bg-muted/50"
+                        : "bg-muted/20"
+                    )}
+                  >
+                    {hour.label}
+                  </th>
+                ))}
+              </tr>
+            </thead>
+            <tbody>
+              {participants.map((p) => {
+                const key = p.email.toLowerCase();
+                const slots = freeBusyData?.get(key);
+                return (
+                  <tr key={key} className="border-b border-border">
+                    <td className="sticky left-0 z-10 bg-background border-r border-border px-3 py-2">
+                      <div className="flex items-center gap-2">
+                        <Avatar
+                          name={p.name}
+                          email={p.email}
+                          size="sm"
+                          className="shrink-0"
+                        />
+                        <div className="min-w-0">
+                          <div className="font-medium truncate">
+                            {p.name || p.email}
+                          </div>
+                          {p.name && (
+                            <div className="text-[10px] text-muted-foreground truncate">
+                              {p.email}
+                            </div>
+                          )}
+                        </div>
+                      </div>
+                    </td>
+                    {hourSlots.map((hour) =>
+                      hour.slots.map((hourSlot, si) => {
+                        const globalSlotIndex =
+                          hourSlots
+                            .slice(0, hourSlots.indexOf(hour))
+                            .reduce((acc, h) => acc + h.slots.length, 0) + si;
+
+                        const slot = slots?.[globalSlotIndex];
+                        const status = slot?.status ?? "unknown";
+                        const isFree = status === "free";
+                        const isHovered =
+                          hoveredSlot?.participant === key &&
+                          hoveredSlot?.slotIndex === globalSlotIndex;
+
+                        return (
+                          <td
+                            key={si}
+                            className={cn(
+                              "border-r border-border py-1 text-center relative cursor-default transition-colors",
+                              statusColors[status],
+                              isFree && statusHoverColors[status],
+                              isFree && "cursor-pointer",
+                              isHovered && "ring-1 ring-inset ring-primary/50",
+                              isWorkingHour(new Date(hourSlot.start).getHours())
+                                ? ""
+                                : "opacity-70"
+                            )}
+                            title={format(hourSlot.start, "HH:mm")}
+                            onClick={() =>
+                              isFree ? handleSlotClick(slot!) : undefined
+                            }
+                            onMouseEnter={() =>
+                              setHoveredSlot({
+                                participant: key,
+                                slotIndex: globalSlotIndex,
+                              })
+                            }
+                            onMouseLeave={() => setHoveredSlot(null)}
+                          >
+                            {status === "free" && (
+                              <span className="block w-full h-full">&nbsp;</span>
+                            )}
+                          </td>
+                        );
+                      })
+                    )}
+                  </tr>
+                );
+              })}
+            </tbody>
+          </table>
+        </div>
+      </div>
+
+      {showNowLine && nowPositionPercent !== null && (
+        <div
+          className="absolute pointer-events-none z-20"
+          style={{
+            left: `calc(180px + ${nowPositionPercent}% * (1 - 180px / ${totalHalfHourSlots * 24 + 200}))`,
+          }}
+        />
+      )}
+
+      <div className="flex items-center gap-3 text-xs text-muted-foreground mt-1">
+        <span className="inline-flex items-center gap-1">
+          <span className="w-3 h-3 rounded border border-emerald-200 dark:border-emerald-800 bg-emerald-100 dark:bg-emerald-900/40" />
+          {t("freeBusy.free")}
+        </span>
+        <span className="inline-flex items-center gap-1">
+          <span className="w-3 h-3 rounded border border-red-200 dark:border-red-800 bg-red-100 dark:bg-red-900/40" />
+          {t("freeBusy.busy")}
+        </span>
+        <span className="inline-flex items-center gap-1">
+          <span className="w-3 h-3 rounded border border-amber-200 dark:border-amber-800 bg-amber-100 dark:bg-amber-900/40" />
+          {t("freeBusy.tentative")}
+        </span>
+        <span className="inline-flex items-center gap-1">
+          <span className="w-3 h-3 rounded border border-purple-200 dark:border-purple-800 bg-purple-100 dark:bg-purple-900/40" />
+          {t("freeBusy.unavailable")}
+        </span>
+        <span className="inline-flex items-center gap-1">
+          <span className="w-3 h-3 rounded border border-muted-foreground/20 bg-muted" />
+          {t("freeBusy.unknown")}
+        </span>
+      </div>
+    </div>
+  );
+}

components/contacts/contact-import-dialog.tsx

@@ -2,26 +2,39 @@
 
 import { useState, useRef, useCallback } from "react";
 import { useTranslations } from "next-intl";
-import { Upload, FileText, AlertTriangle, X, Check } from "lucide-react";
+import { Upload, FileText, AlertTriangle, X, Check, ChevronDown } from "lucide-react";
 import { Button } from "@/components/ui/button";
 import { cn } from "@/lib/utils";
 import { parseVCard, detectDuplicates } from "@/lib/vcard";
-import type { ContactCard } from "@/lib/jmap/types";
+import type { ContactCard, AddressBook } from "@/lib/jmap/types";
 import { getContactDisplayName, getContactPrimaryEmail } from "@/stores/contact-store";
+import {
+  parseCSV,
+  autoMapColumns,
+  mapRowToContact,
+  detectDuplicatesByEmail,
+  type CsvColumnMapping,
+  type CsvParseResult,
+} from "@/lib/contact-csv-import";
+
+type FileType = "vcf" | "csv" | null;
 
 interface ContactImportDialogProps {
   existingContacts: ContactCard[];
+  addressBooks?: AddressBook[];
   onImport: (contacts: ContactCard[]) => Promise<number>;
   onClose: () => void;
 }
 
 export function ContactImportDialog({
   existingContacts,
+  addressBooks,
   onImport,
   onClose,
 }: ContactImportDialogProps) {
   const t = useTranslations("contacts");
   const fileRef = useRef<HTMLInputElement>(null);
+  const [fileType, setFileType] = useState<FileType>(null);
   const [parsed, setParsed] = useState<ContactCard[]>([]);
   const [selected, setSelected] = useState<Set<number>>(new Set());
   const [duplicates, setDuplicates] = useState<Map<number, string>>(new Map());
@@ -29,41 +42,111 @@ export function ContactImportDialog({
   const [result, setResult] = useState<number | null>(null);
   const [error, setError] = useState<string | null>(null);
 
+  const [csvData, setCsvData] = useState<CsvParseResult | null>(null);
+  const [mapping, setMapping] = useState<CsvColumnMapping | null>(null);
+  const [targetBookId, setTargetBookId] = useState("");
+  const [showPreview, setShowPreview] = useState(false);
+
+  const ALLOWED_ACCEPT = ".vcf,.vcard,.csv,text/csv,text/vcard";
+
+  const books = addressBooks || [];
+  const defaultBookId =
+    books.find((b) => b.isDefault)?.id || books[0]?.id || "";
+  const effectiveBookId = targetBookId || defaultBookId;
+  const bookOptions = books.map((b) => ({
+    value: b.id,
+    label: b.name,
+  }));
+
   const handleFileChange = useCallback(async (e: React.ChangeEvent<HTMLInputElement>) => {
     const file = e.target.files?.[0];
     if (!file) return;
 
     setError(null);
     setResult(null);
+    setFileType(null);
+    setParsed([]);
+    setSelected(new Set());
+    setDuplicates(new Map());
+    setCsvData(null);
+    setMapping(null);
+    setShowPreview(false);
+    setTargetBookId("");
 
-    if (file.size > 5 * 1024 * 1024) {
+    if (file.size > 10 * 1024 * 1024) {
       setError(t("import.file_too_large"));
       return;
     }
 
+    const name = file.name.toLowerCase();
+
     try {
-      const text = await file.text();
+      if (name.endsWith(".csv") || file.type === "text/csv") {
-      const contacts = parseVCard(text);
+        setFileType("csv");
+        const text = await file.text();
+        const result = parseCSV(text);
 
-      if (contacts.length === 0) {
+        if (result.rows.length === 0) {
-        setError(t("import.no_contacts"));
+          setError(t("import.no_contacts"));
-        return;
+          return;
+        }
+
+        setCsvData(result);
+        setMapping(autoMapColumns(result.headers));
+        setTargetBookId(defaultBookId);
+      } else {
+        setFileType("vcf");
+        const text = await file.text();
+        const contacts = parseVCard(text);
+
+        if (contacts.length === 0) {
+          setError(t("import.no_contacts"));
+          return;
+        }
+
+        const dupes = detectDuplicates(existingContacts, contacts);
+        setParsed(contacts);
+        setDuplicates(dupes);
+
+        const initialSelected = new Set<number>();
+        contacts.forEach((_, idx) => {
+          if (!dupes.has(idx)) initialSelected.add(idx);
+        });
+        setSelected(initialSelected);
       }
-
+    } catch (err) {
-      const dupes = detectDuplicates(existingContacts, contacts);
+      console.error("Failed to parse file:", err);
-      setParsed(contacts);
-      setDuplicates(dupes);
-
-      const initialSelected = new Set<number>();
-      contacts.forEach((_, idx) => {
-        if (!dupes.has(idx)) initialSelected.add(idx);
-      });
-      setSelected(initialSelected);
-    } catch (error) {
-      console.error('Failed to parse vCard:', error);
       setError(t("import.parse_error"));
     }
-  }, [existingContacts, t]);
+  }, [existingContacts, t, defaultBookId]);
+
+  const applyCsvMapping = useCallback(() => {
+    if (!csvData || !mapping) return;
+
+    const bookIds = effectiveBookId ? { [effectiveBookId]: true } : {};
+    const contacts: ContactCard[] = [];
+
+    for (const row of csvData.rows) {
+      const contact = mapRowToContact(row, mapping, bookIds);
+      if (contact) contacts.push(contact);
+    }
+
+    if (contacts.length === 0) {
+      setError(t("import.no_contacts"));
+      return;
+    }
+
+    const dupes = detectDuplicatesByEmail(existingContacts, contacts);
+    setParsed(contacts);
+    setDuplicates(dupes);
+
+    const initialSelected = new Set<number>();
+    contacts.forEach((_, idx) => {
+      if (!dupes.has(idx)) initialSelected.add(idx);
+    });
+    setSelected(initialSelected);
+    setShowPreview(true);
+  }, [csvData, mapping, effectiveBookId, existingContacts, t]);
 
   const toggleSelect = (idx: number) => {
     const next = new Set(selected);
@@ -91,14 +174,160 @@ export function ContactImportDialog({
     try {
       const count = await onImport(toImport);
       setResult(count);
-    } catch (error) {
+    } catch (err) {
-      console.error('Failed to import contacts:', error);
+      console.error("Failed to import contacts:", err);
       setError(t("import.failed"));
     } finally {
       setIsImporting(false);
     }
   };
 
+  const renderCsvMapping = () => {
+    if (!csvData || !mapping) return null;
+
+    const fields: Array<{ key: keyof CsvColumnMapping; label: string }> = [
+      { key: "firstName", label: t("import.csv_first_name") },
+      { key: "lastName", label: t("import.csv_last_name") },
+      { key: "email", label: t("import.csv_email") },
+      { key: "phone", label: t("import.csv_phone") },
+      { key: "company", label: t("import.csv_company") },
+      { key: "jobTitle", label: t("import.csv_job_title") },
+      { key: "address", label: t("import.csv_address") },
+      { key: "city", label: t("import.csv_city") },
+      { key: "region", label: t("import.csv_region") },
+      { key: "postcode", label: t("import.csv_postcode") },
+      { key: "country", label: t("import.csv_country") },
+      { key: "website", label: t("import.csv_website") },
+      { key: "note", label: t("import.csv_note") },
+      { key: "nickname", label: t("import.csv_nickname") },
+    ];
+
+    const headerOptions = csvData.headers.map((h, i) => ({
+      value: String(i),
+      label: h,
+    }));
+
+    return (
+      <div className="space-y-3">
+        <p className="text-sm font-medium">{t("import.csv_map_columns")}</p>
+        <div className="grid grid-cols-2 gap-2 max-h-64 overflow-y-auto">
+          {fields.map(({ key, label }) => (
+            <div key={key} className="flex items-center gap-2">
+              <label className="text-xs text-muted-foreground w-24 flex-shrink-0 truncate">
+                {label}
+              </label>
+              <select
+                value={mapping[key] >= 0 ? String(mapping[key]) : "-1"}
+                onChange={(e) => {
+                  setMapping((prev) => prev ? {
+                    ...prev,
+                    [key]: parseInt(e.target.value, 10),
+                  } : null);
+                }}
+                className="flex-1 px-2 py-1 text-xs rounded border border-border bg-muted text-foreground focus:outline-none focus:ring-1 focus:ring-ring"
+                dir="auto"
+              >
+                <option value="-1">{t("import.csv_ignore")}</option>
+                {headerOptions.map((opt) => (
+                  <option key={opt.value} value={opt.value}>
+                    {opt.label}
+                  </option>
+                ))}
+              </select>
+            </div>
+          ))}
+        </div>
+
+        {books.length > 0 && (
+          <div className="flex items-center gap-2 pt-2">
+            <label className="text-xs text-muted-foreground flex-shrink-0">
+              {t("import.csv_address_book")}
+            </label>
+            <select
+              value={effectiveBookId}
+              onChange={(e) => setTargetBookId(e.target.value)}
+              className="px-2 py-1 text-xs rounded border border-border bg-muted text-foreground focus:outline-none focus:ring-1 focus:ring-ring"
+              dir="auto"
+            >
+              {bookOptions.map((opt) => (
+                <option key={opt.value} value={opt.value}>
+                  {opt.label}
+                </option>
+              ))}
+            </select>
+          </div>
+        )}
+
+        <div className="flex gap-2 pt-1">
+          <Button size="sm" onClick={applyCsvMapping}>
+            {t("import.csv_preview")}
+          </Button>
+          <Button
+            variant="ghost"
+            size="sm"
+            onClick={() => {
+              setFileType(null);
+              setCsvData(null);
+              setMapping(null);
+              if (fileRef.current) fileRef.current.value = "";
+            }}
+          >
+            {t("form.cancel")}
+          </Button>
+        </div>
+      </div>
+    );
+  };
+
+  const renderCsvPreview = () => {
+    if (!csvData || !mapping || !showPreview) return null;
+    const previewRows = csvData.rows.slice(0, 5);
+
+    return (
+      <div className="space-y-3">
+        <div className="flex items-center justify-between">
+          <p className="text-sm font-medium">{t("import.csv_preview_title", { count: parsed.length })}</p>
+          <Button
+            variant="ghost"
+            size="sm"
+            onClick={() => setShowPreview(false)}
+          >
+            {t("import.csv_back")}
+          </Button>
+        </div>
+        <div className="border rounded-md overflow-x-auto">
+          <table className="w-full text-xs">
+            <thead>
+              <tr className="bg-muted">
+                {csvData.headers.map((h, i) => (
+                  <th key={i} className="px-2 py-1.5 text-start font-medium text-muted-foreground whitespace-nowrap">
+                    {h}
+                  </th>
+                ))}
+              </tr>
+            </thead>
+            <tbody>
+              {previewRows.map((row, ri) => (
+                <tr key={ri} className="border-t border-border">
+                  {row.map((cell, ci) => (
+                    <td key={ci} className="px-2 py-1.5 truncate max-w-[150px]">
+                      {cell}
+                    </td>
+                  ))}
+                </tr>
+              ))}
+            </tbody>
+          </table>
+        </div>
+        <div className="flex gap-2">
+          <Button size="sm" onClick={applyCsvMapping}>
+            {t("import.csv_load_all")}
+          </Button>
+        </div>
+      </div>
+    );
+  };
+
   return (
     <div className="flex flex-col h-full">
       <div className="px-6 py-4 border-b border-border flex items-center justify-between">
@@ -119,12 +348,12 @@ export function ContactImportDialog({
               {t("import.close")}
             </Button>
           </div>
-        ) : parsed.length === 0 ? (
+        ) : fileType === null ? (
           <>
             <input
               ref={fileRef}
               type="file"
-              accept=".vcf,.vcard"
+              accept={ALLOWED_ACCEPT}
               onChange={handleFileChange}
               className="hidden"
             />
@@ -141,7 +370,7 @@ export function ContactImportDialog({
             >
               <Upload className="w-8 h-8" />
               <p className="text-sm font-medium">{t("import.drop_hint")}</p>
-              <p className="text-xs">{t("import.file_types")}</p>
+              <p className="text-xs">{t("import.file_types_csv")}</p>
             </button>
 
             {error && (
@@ -151,6 +380,10 @@ export function ContactImportDialog({
               </div>
             )}
           </>
+        ) : fileType === "csv" && csvData && !showPreview ? (
+          renderCsvMapping()
+        ) : fileType === "csv" && csvData && showPreview ? (
+          renderCsvPreview()
         ) : (
           <>
             {error && (
@@ -217,7 +450,23 @@ export function ContactImportDialog({
         )}
       </div>
 
-      {parsed.length > 0 && result === null && (
+      {parsed.length > 0 && result === null && fileType !== "csv" && (
+        <div className="flex items-center justify-between px-6 py-4 border-t border-border">
+          <p className="text-sm text-muted-foreground">
+            {t("import.selected", { count: selected.size })}
+          </p>
+          <div className="flex gap-2">
+            <Button variant="outline" onClick={onClose} disabled={isImporting}>
+              {t("form.cancel")}
+            </Button>
+            <Button onClick={handleImport} disabled={isImporting || selected.size === 0}>
+              {isImporting ? t("import.importing") : t("import.import_button")}
+            </Button>
+          </div>
+        </div>
+      )}
+
+      {fileType === "csv" && showPreview && parsed.length > 0 && result === null && (
         <div className="flex items-center justify-between px-6 py-4 border-t border-border">
           <p className="text-sm text-muted-foreground">
             {t("import.selected", { count: selected.size })}

components/layout/mailbox-context-menu.tsx

@@ -21,6 +21,7 @@ import {
   FolderX,
   RefreshCw,
   Upload,
+  Share2,
 } from "lucide-react";
 
 interface Position {
@@ -86,6 +87,7 @@ interface MailboxContextMenuProps {
   onRenameFolder?: (mailboxId: string) => void;
   onDeleteFolder?: (mailboxId: string) => void;
   onImportEmail?: (mailboxId: string) => void;
+  onShareFolder?: (mailboxId: string) => void;
   onRefresh?: () => void;
 }
 
@@ -105,6 +107,7 @@ export function MailboxContextMenu({
   onRenameFolder,
   onDeleteFolder,
   onImportEmail,
+  onShareFolder,
   onRefresh,
 }: MailboxContextMenuProps) {
   const t = useTranslations("mailbox_context_menu");
@@ -191,6 +194,12 @@ export function MailboxContextMenu({
         onClick={() => handleAction(() => onRenameFolder?.(mailbox.id))}
         disabled={!onRenameFolder || !canRename}
       />
+      <ContextMenuItem
+        icon={Share2}
+        label={t("share_folder")}
+        onClick={() => handleAction(() => onShareFolder?.(mailbox.id))}
+        disabled={!onShareFolder || mailbox.isShared}
+      />
 
       <ContextMenuSeparator />
 

components/layout/sidebar.tsx

@@ -90,6 +90,7 @@ interface SidebarProps {
   onDeleteFolder?: (mailboxId: string) => void;
   onImportEmail?: (mailboxId: string) => void;
   onRefreshMailboxes?: () => void;
+  onShareFolder?: (mailboxId: string) => void;
   scheduledTotal?: number;
   showScheduledMailbox?: boolean;
   /** True when the unified view spans multiple login accounts (cross-account).
@@ -779,6 +780,7 @@ export function Sidebar({
   onDeleteFolder,
   onImportEmail,
   onRefreshMailboxes,
+  onShareFolder,
   scheduledTotal = 0,
   showScheduledMailbox = false,
   crossAccountActive = false,
@@ -1452,6 +1454,7 @@ export function Sidebar({
         onRenameFolder={onRenameFolder}
         onDeleteFolder={onDeleteFolder}
         onImportEmail={onImportEmail}
+        onShareFolder={onShareFolder}
         onRefresh={onRefreshMailboxes}
       />
     </div>

components/settings/contacts-settings.tsx

@@ -18,6 +18,7 @@ export function ContactsSettings() {
   const { client } = useAuthStore();
   const {
     contacts,
+    addressBooks,
     supportsSync,
     importContacts,
   } = useContactStore();
@@ -46,6 +47,7 @@ export function ContactsSettings() {
       <div className="border border-border rounded-lg overflow-hidden" style={{ minHeight: 400 }}>
         <ContactImportDialog
           existingContacts={contacts}
+          addressBooks={addressBooks}
           onImport={handleImport}
           onClose={() => setShowImport(false)}
         />

components/settings/import-settings.tsx

@@ -0,0 +1,245 @@
+"use client";
+
+import { useState, useRef, useCallback, useEffect } from "react";
+import { useTranslations } from "next-intl";
+import { Upload, FolderOpen, Download, AlertTriangle, Check, X } from "lucide-react";
+import { Button } from "@/components/ui/button";
+import { SettingsSection, SettingItem, RadioGroup, Select } from "./settings-section";
+import { importEmails, type ConflictResolution, type ImportProgress, type ImportResult } from "@/lib/email-import";
+import { useAuthStore } from "@/stores/auth-store";
+import { useEmailStore } from "@/stores/email-store";
+import { EML_IMPORT_ACCEPT } from "@/lib/eml-import";
+import { toast } from "@/stores/toast-store";
+import { cn } from "@/lib/utils";
+
+export function ImportSettings() {
+  const t = useTranslations("settings.importer");
+  const { client } = useAuthStore();
+  const { mailboxes } = useEmailStore();
+  const fileRef = useRef<HTMLInputElement>(null);
+  const [files, setFiles] = useState<File[]>([]);
+  const [destination, setDestination] = useState("");
+  const [conflict, setConflict] = useState<ConflictResolution>("skip");
+  const [progress, setProgress] = useState<ImportProgress | null>(null);
+  const [result, setResult] = useState<ImportResult | null>(null);
+  const [error, setError] = useState<string | null>(null);
+  const [importing, setImporting] = useState(false);
+  const abortRef = useRef<AbortController | null>(null);
+
+  useEffect(() => {
+    if (mailboxes.length > 0 && !destination) {
+      const inbox = mailboxes.find((m) => m.role === "inbox") || mailboxes[0];
+      if (inbox) setDestination(inbox.id);
+    }
+  }, [mailboxes, destination]);
+
+  const folderOptions = mailboxes.map((m) => ({
+    value: m.id,
+    label: m.name,
+  }));
+
+  const handleFileChange = useCallback((e: React.ChangeEvent<HTMLInputElement>) => {
+    const selected = e.target.files;
+    if (!selected || selected.length === 0) return;
+    setError(null);
+    setResult(null);
+    setProgress(null);
+    setFiles(Array.from(selected));
+  }, []);
+
+  const handleImport = useCallback(async () => {
+    if (!client || files.length === 0 || !destination) return;
+
+    setImporting(true);
+    setError(null);
+    setResult(null);
+    const controller = new AbortController();
+    abortRef.current = controller;
+
+    try {
+      const res = await importEmails({
+        client,
+        files,
+        destinationMailboxId: destination,
+        conflictResolution: conflict,
+        onProgress: (p) => setProgress({ ...p }),
+        signal: controller.signal,
+      });
+      setResult(res);
+      if (res.imported > 0) {
+        toast.success(t("success", { count: res.imported }));
+      }
+    } catch (err) {
+      if (!controller.signal.aborted) {
+        const msg = err instanceof Error ? err.message : t("fail");
+        setError(msg);
+        toast.error(msg);
+      }
+    } finally {
+      setImporting(false);
+      abortRef.current = null;
+    }
+  }, [client, files, destination, conflict, t]);
+
+  const handleCancel = () => {
+    abortRef.current?.abort();
+    setImporting(false);
+  };
+
+  const reset = () => {
+    setFiles([]);
+    setResult(null);
+    setProgress(null);
+    setError(null);
+    if (fileRef.current) fileRef.current.value = "";
+  };
+
+  const progressPercent = progress && progress.total > 0
+    ? Math.round((progress.processed / progress.total) * 100)
+    : 0;
+
+  return (
+    <SettingsSection
+      title={t("title")}
+      description={t("description")}
+    >
+      <SettingItem
+        label={t("file_label")}
+        description={t("file_description")}
+      >
+        <div className="flex items-center gap-2">
+          <input
+            ref={fileRef}
+            type="file"
+            accept={EML_IMPORT_ACCEPT}
+            multiple
+            onChange={handleFileChange}
+            className="hidden"
+          />
+          <Button
+            variant="outline"
+            size="sm"
+            onClick={() => fileRef.current?.click()}
+            disabled={importing}
+          >
+            <Upload className="w-4 h-4 me-2" />
+            {files.length > 0
+              ? t("files_selected", { count: files.length })
+              : t("choose_files")}
+          </Button>
+          {files.length > 0 && !importing && (
+            <Button variant="ghost" size="sm" onClick={reset}>
+              <X className="w-4 h-4" />
+            </Button>
+          )}
+        </div>
+      </SettingItem>
+
+      <SettingItem
+        label={t("folder_label")}
+        description={t("folder_description")}
+      >
+        <Select
+          value={destination}
+          onChange={setDestination}
+          options={folderOptions}
+          disabled={importing || folderOptions.length === 0}
+        />
+      </SettingItem>
+
+      <SettingItem
+        label={t("conflict_label")}
+        description={t("conflict_description")}
+      >
+        <RadioGroup
+          value={conflict}
+          onChange={(v) => setConflict(v as ConflictResolution)}
+          options={[
+            { value: "skip", label: t("conflict_skip") },
+            { value: "replace", label: t("conflict_replace") },
+            { value: "copy", label: t("conflict_copy") },
+          ]}
+        />
+      </SettingItem>
+
+      {files.length > 0 && !result && (
+        <SettingItem label={t("action_label")} description="">
+          <Button
+            onClick={handleImport}
+            disabled={importing || !destination}
+          >
+            {importing ? t("importing") : t("start_import", { count: files.length })}
+          </Button>
+        </SettingItem>
+      )}
+
+      {error && (
+        <div className="text-sm text-red-600 dark:text-red-400 bg-red-50 dark:bg-red-950 px-3 py-2 rounded flex items-center gap-2">
+          <AlertTriangle className="w-4 h-4 flex-shrink-0" />
+          {error}
+        </div>
+      )}
+
+      {progress && importing && (
+        <div className="space-y-2">
+          <div className="flex items-center justify-between text-sm text-muted-foreground">
+            <span>{progress.currentFile}</span>
+            <span>{progressPercent}%</span>
+          </div>
+          <div className="w-full bg-muted rounded-full h-2">
+            <div
+              className="bg-primary h-2 rounded-full transition-all duration-300"
+              style={{ width: `${progressPercent}%` }}
+            />
+          </div>
+          <div className="flex justify-between text-xs text-muted-foreground">
+            <span>{t("progress_imported", { count: progress.imported })}</span>
+            <span>{t("progress_skipped", { count: progress.skipped })}</span>
+            <span>{t("progress_failed", { count: progress.failed })}</span>
+          </div>
+          <div className="flex justify-center">
+            <Button variant="outline" size="sm" onClick={handleCancel}>
+              {t("cancel")}
+            </Button>
+          </div>
+        </div>
+      )}
+
+      {result && !importing && (
+        <div className={cn(
+          "rounded-lg p-4 space-y-3",
+          result.failed > 0
+            ? "bg-warning/10 border border-warning/30"
+            : "bg-green-50 dark:bg-green-950 border border-green-200 dark:border-green-800"
+        )}>
+          <div className="flex items-center gap-2">
+            <Check className="w-5 h-5 text-green-600 dark:text-green-400" />
+            <span className="font-medium text-sm">{t("import_complete")}</span>
+          </div>
+          <div className="text-sm space-y-1">
+            <p>{t("summary_imported", { count: result.imported })}</p>
+            <p>{t("summary_skipped", { count: result.skipped })}</p>
+            <p>{t("summary_failed", { count: result.failed })}</p>
+          </div>
+          {result.errors.length > 0 && (
+            <details className="text-xs">
+              <summary className="cursor-pointer text-muted-foreground hover:text-foreground">
+                {t("error_details", { count: result.errors.length })}
+              </summary>
+              <ul className="mt-2 space-y-1 ps-4 list-disc">
+                {result.errors.map((e, i) => (
+                  <li key={i} className="text-red-600 dark:text-red-400">
+                    <span className="font-medium">{e.file}</span>: {e.error}
+                  </li>
+                ))}
+              </ul>
+            </details>
+          )}
+          <Button variant="outline" size="sm" onClick={reset}>
+            {t("import_more")}
+          </Button>
+        </div>
+      )}
+    </SettingsSection>
+  );
+}

components/settings/sharing-settings.tsx

@@ -0,0 +1,279 @@
+"use client";
+
+import { useEffect, useState, useCallback } from "react";
+import { useTranslations } from "next-intl";
+import { Button } from "@/components/ui/button";
+import { Avatar } from "@/components/ui/avatar";
+import {
+  Loader2,
+  RefreshCw,
+  Check,
+  X,
+  Folder,
+  Calendar,
+  BookUser,
+  HardDrive,
+  Trash2,
+} from "lucide-react";
+import { cn } from "@/lib/utils";
+import { useAuthStore } from "@/stores/auth-store";
+import { useSharingStore, type SharedResourceKind, type SharedFolder } from "@/stores/sharing-store";
+
+const ICON_CLASS = "w-4 h-4 shrink-0";
+
+function KindIcon({ kind }: { kind: SharedResourceKind }) {
+  switch (kind) {
+    case "mailbox":
+      return <Folder className={cn(ICON_CLASS, "text-blue-600/80")} />;
+    case "calendar":
+      return <Calendar className={cn(ICON_CLASS, "text-emerald-600/80")} />;
+    case "addressBook":
+      return <BookUser className={cn(ICON_CLASS, "text-violet-600/80")} />;
+    case "file":
+      return <HardDrive className={cn(ICON_CLASS, "text-amber-600/80")} />;
+  }
+}
+
+function KindLabel({ kind }: { kind: SharedResourceKind }) {
+  switch (kind) {
+    case "mailbox":
+      return "Mail";
+    case "calendar":
+      return "Calendar";
+    case "addressBook":
+      return "Contacts";
+    case "file":
+      return "Files";
+  }
+}
+
+export function SharingSettings() {
+  const t = useTranslations("settings");
+  const tSharing = useTranslations("sharing");
+  const client = useAuthStore((s) => s.client);
+  const {
+    sharedByMe,
+    sharedWithMe,
+    loading,
+    fetchShares,
+    revokeShare,
+    changeRole,
+    acceptShare,
+    declineShare,
+  } = useSharingStore();
+  const [activeTab, setActiveTab] = useState<"byMe" | "withMe">("byMe");
+
+  const handleRefresh = useCallback(() => {
+    if (client) fetchShares(client);
+  }, [client, fetchShares]);
+
+  useEffect(() => {
+    if (client) handleRefresh();
+  }, [client, handleRefresh]);
+
+  const handleRevoke = async (share: SharedFolder) => {
+    if (!client) return;
+    await revokeShare(
+      client,
+      share.resourceId,
+      share.resourceKind,
+      share.principalId,
+      share.accountId,
+    );
+  };
+
+  const handleChangeRole = async (share: SharedFolder, role: string) => {
+    if (!client) return;
+    await changeRole(
+      client,
+      share.resourceId,
+      share.resourceKind,
+      share.principalId,
+      role,
+      share.accountId,
+    );
+  };
+
+  const handleAccept = async (share: SharedFolder) => {
+    if (!client) return;
+    await acceptShare(client, share);
+  };
+
+  const handleDecline = async (share: SharedFolder) => {
+    if (!client) return;
+    await declineShare(client, share);
+  };
+
+  return (
+    <div>
+      <div className="flex items-center gap-1 border-b border-border mb-4">
+        <button
+          onClick={() => setActiveTab("byMe")}
+          className={cn(
+            "px-4 py-2 text-sm font-medium border-b-2 transition-colors -mb-px",
+            activeTab === "byMe"
+              ? "border-primary text-primary"
+              : "border-transparent text-muted-foreground hover:text-foreground",
+          )}
+        >
+          {tSharing("tab_shared_by_me")}
+        </button>
+        <button
+          onClick={() => setActiveTab("withMe")}
+          className={cn(
+            "px-4 py-2 text-sm font-medium border-b-2 transition-colors -mb-px",
+            activeTab === "withMe"
+              ? "border-primary text-primary"
+              : "border-transparent text-muted-foreground hover:text-foreground",
+          )}
+        >
+          {tSharing("tab_shared_with_me")}
+        </button>
+        <div className="flex-1" />
+        <button
+          onClick={handleRefresh}
+          disabled={loading}
+          className="p-2 rounded-md hover:bg-muted text-muted-foreground disabled:opacity-50 transition-colors"
+          title={t("refresh")}
+        >
+          <RefreshCw
+            className={cn("w-4 h-4", loading && "animate-spin")}
+          />
+        </button>
+      </div>
+
+      {loading && (
+        <div className="flex items-center justify-center py-8 text-muted-foreground">
+          <Loader2 className="w-5 h-5 animate-spin me-2" />
+          {t("loading")}
+        </div>
+      )}
+
+      {!loading && activeTab === "byMe" && (
+        <>
+          {sharedByMe.length === 0 ? (
+            <div className="text-sm text-muted-foreground py-8 text-center">
+              {tSharing("no_shares_by_me")}
+            </div>
+          ) : (
+            <div className="space-y-1">
+              {sharedByMe.map((share) => (
+                <div
+                  key={share.id}
+                  className="flex items-center gap-3 px-3 py-2.5 rounded-md border border-border bg-card"
+                >
+                  <KindIcon kind={share.resourceKind} />
+                  <div className="flex-1 min-w-0">
+                    <div className="text-sm font-medium truncate">
+                      {share.resourceName}
+                    </div>
+                    <div className="text-xs text-muted-foreground flex items-center gap-1">
+                      <KindLabel kind={share.resourceKind} />
+                      <span className="mx-1 opacity-40">|</span>
+                      <Avatar
+                        name={share.principalName}
+                        email={share.principalEmail ?? undefined}
+                        size="sm"
+                        className="shrink-0 me-1"
+                      />
+                      <span className="truncate">{share.principalName}</span>
+                    </div>
+                  </div>
+                  <select
+                    value={share.role}
+                    onChange={(e) => handleChangeRole(share, e.target.value)}
+                    className="appearance-none rounded-md border border-input bg-background px-2 py-1 text-xs focus:outline-none focus:ring-2 focus:ring-ring"
+                  >
+                    <option value="read">
+                      {tSharing("preset.read")}
+                    </option>
+                    <option value="readWrite">
+                      {tSharing("preset.readWrite")}
+                    </option>
+                    <option value="manager">
+                      {tSharing("preset.manager")}
+                    </option>
+                  </select>
+                  <button
+                    onClick={() => handleRevoke(share)}
+                    className="p-1.5 rounded-md hover:bg-destructive/10 text-muted-foreground hover:text-destructive transition-colors"
+                    title={tSharing("remove")}
+                  >
+                    <Trash2 className="w-4 h-4" />
+                  </button>
+                </div>
+              ))}
+            </div>
+          )}
+        </>
+      )}
+
+      {!loading && activeTab === "withMe" && (
+        <>
+          {sharedWithMe.length === 0 ? (
+            <div className="text-sm text-muted-foreground py-8 text-center">
+              {tSharing("no_shares_with_me")}
+            </div>
+          ) : (
+            <div className="space-y-1">
+              {sharedWithMe.map((share) => (
+                <div
+                  key={share.id}
+                  className="flex items-center gap-3 px-3 py-2.5 rounded-md border border-border bg-card"
+                >
+                  <KindIcon kind={share.resourceKind} />
+                  <div className="flex-1 min-w-0">
+                    <div className="text-sm font-medium truncate">
+                      {share.resourceName}
+                    </div>
+                    <div className="text-xs text-muted-foreground flex items-center gap-1">
+                      <KindLabel kind={share.resourceKind} />
+                      <span className="mx-1 opacity-40">|</span>
+                      <span className="truncate">
+                        {tSharing("shared_by")}: {share.principalName}
+                      </span>
+                    </div>
+                  </div>
+                  <span className="text-xs bg-muted rounded px-2 py-0.5 text-muted-foreground">
+                    {tSharing(`preset.${share.role}`)}
+                  </span>
+                  {share.pending ? (
+                    <div className="flex items-center gap-1">
+                      <Button
+                        size="sm"
+                        variant="default"
+                        onClick={() => handleAccept(share)}
+                        className="h-7 px-2 text-xs"
+                      >
+                        <Check className="w-3 h-3 me-1" />
+                        {tSharing("accept")}
+                      </Button>
+                      <Button
+                        size="sm"
+                        variant="ghost"
+                        onClick={() => handleDecline(share)}
+                        className="h-7 px-2 text-xs"
+                      >
+                        <X className="w-3 h-3 me-1" />
+                        {tSharing("decline")}
+                      </Button>
+                    </div>
+                  ) : (
+                    <Button
+                      size="sm"
+                      variant="ghost"
+                      onClick={() => handleDecline(share)}
+                      className="h-7 px-2 text-xs text-muted-foreground hover:text-destructive"
+                    >
+                      {tSharing("remove")}
+                    </Button>
+                  )}
+                </div>
+              ))}
+            </div>
+          )}
+        </>
+      )}
+    </div>
+  );
+}

components/sharing/share-folder-dialog.tsx

@@ -0,0 +1,383 @@
+"use client";
+
+import { useEffect, useMemo, useRef, useState } from "react";
+import { useTranslations } from "next-intl";
+import { Button } from "@/components/ui/button";
+import { Avatar } from "@/components/ui/avatar";
+import {
+  X,
+  Loader2,
+  UserPlus,
+  Trash2,
+  Users,
+  ChevronDown,
+} from "lucide-react";
+import type { IJMAPClient } from "@/lib/jmap/client-interface";
+import type { Principal } from "@/lib/jmap/types";
+import { useSharingStore, type SharedResourceKind } from "@/stores/sharing-store";
+
+export interface ShareFolderDialogProps {
+  client: IJMAPClient;
+  resourceId: string;
+  resourceName: string;
+  resourceKind: SharedResourceKind;
+  onClose: () => void;
+}
+
+const PRESET_OPTIONS: Record<SharedResourceKind, readonly string[]> = {
+  mailbox: ["read", "readWrite", "manager"],
+  calendar: ["read", "readWrite", "manager"],
+  addressBook: ["read", "readWrite", "manager"],
+  file: ["read", "readWrite", "manager"],
+};
+
+export function ShareFolderDialog({
+  client,
+  resourceId,
+  resourceName,
+  resourceKind,
+  onClose,
+}: ShareFolderDialogProps) {
+  const t = useTranslations("sharing");
+  const tCommon = useTranslations("common");
+  const modalRef = useRef<HTMLDivElement>(null);
+
+  const sharedByMe = useSharingStore((s) => s.sharedByMe);
+  const loadPrincipals = useSharingStore((s) => s.loadPrincipals);
+  const shareFolder = useSharingStore((s) => s.shareFolder);
+  const revokeShare = useSharingStore((s) => s.revokeShare);
+  const changeRole = useSharingStore((s) => s.changeRole);
+
+  const [allPrincipals, setAllPrincipals] = useState<Principal[]>([]);
+  const [loadingPrincipals, setLoadingPrincipals] = useState(true);
+  const [search, setSearch] = useState("");
+  const [savingId, setSavingId] = useState<string | null>(null);
+  const [showAdd, setShowAdd] = useState(false);
+  const [message, setMessage] = useState("");
+
+  useEffect(() => {
+    let cancelled = false;
+    setLoadingPrincipals(true);
+    loadPrincipals(client)
+      .then((list) => {
+        if (cancelled) return;
+        setAllPrincipals(list);
+        setLoadingPrincipals(false);
+      })
+      .catch(() => {
+        if (!cancelled) setLoadingPrincipals(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, [client, loadPrincipals]);
+
+  const ownAccountId = client.getAccountId();
+
+  const allPrincipalsById = useMemo(() => {
+    const map = new Map<string, Principal>();
+    for (const p of allPrincipals) map.set(p.id, p);
+    return map;
+  }, [allPrincipals]);
+
+  const currentShares = sharedByMe.filter(
+    (f) => f.resourceId === resourceId && f.resourceKind === resourceKind,
+  );
+
+  const principals = useMemo(() => {
+    const existing = new Set(currentShares.map((s) => s.principalId));
+    return allPrincipals.filter(
+      (p) => p.id !== ownAccountId && !existing.has(p.id),
+    );
+  }, [allPrincipals, ownAccountId, currentShares]);
+
+  useEffect(() => {
+    const onKey = (e: KeyboardEvent) => {
+      if (e.key === "Escape") onClose();
+    };
+    document.addEventListener("keydown", onKey);
+    return () => document.removeEventListener("keydown", onKey);
+  }, [onClose]);
+
+  const handleRemove = async (principalId: string) => {
+    setSavingId(principalId);
+    try {
+      await revokeShare(client, resourceId, resourceKind, principalId);
+    } catch {
+      /* error toast comes from store */
+    } finally {
+      setSavingId(null);
+    }
+  };
+
+  const handleChangeRole = async (principalId: string, role: string) => {
+    setSavingId(principalId);
+    try {
+      await changeRole(client, resourceId, resourceKind, principalId, role);
+    } catch {
+      /* error toast comes from store */
+    } finally {
+      setSavingId(null);
+    }
+  };
+
+  const handleAdd = async (principal: Principal) => {
+    setSavingId(principal.id);
+    try {
+      await shareFolder(
+        client,
+        resourceId,
+        resourceName,
+        resourceKind,
+        principal.id,
+        "read",
+        message || undefined,
+      );
+      setShowAdd(false);
+      setSearch("");
+      setMessage("");
+    } catch {
+      /* error toast comes from store */
+    } finally {
+      setSavingId(null);
+    }
+  };
+
+  const filteredPrincipals = useMemo(() => {
+    const q = search.trim().toLowerCase();
+    if (!q) return principals;
+    return principals.filter(
+      (p) =>
+        p.name.toLowerCase().includes(q) ||
+        p.email?.toLowerCase().includes(q) ||
+        p.description?.toLowerCase().includes(q),
+    );
+  }, [principals, search]);
+
+  const presetOptions = PRESET_OPTIONS[resourceKind];
+
+  const kindLabels: Record<SharedResourceKind, string> = {
+    mailbox: "Mail folder",
+    calendar: "Calendar",
+    addressBook: "Address book",
+    file: "File folder",
+  };
+
+  return (
+    <div className="fixed inset-0 z-50 flex items-center justify-center">
+      <div
+        className="absolute inset-0 bg-black/50 backdrop-blur-[1px]"
+        onClick={onClose}
+        aria-hidden="true"
+      />
+      <div
+        ref={modalRef}
+        role="dialog"
+        aria-modal="true"
+        aria-label={t("title", { name: resourceName })}
+        className="relative bg-background border border-border rounded-lg shadow-xl w-full max-w-lg mx-4 animate-in zoom-in-95 duration-200 max-h-[85vh] flex flex-col"
+      >
+        <div className="flex items-center justify-between px-6 py-4 border-b border-border">
+          <div className="flex items-center gap-2">
+            <Users className="w-5 h-5 text-primary" />
+            <div>
+              <h2 className="text-lg font-semibold">
+                {t("title", { name: resourceName })}
+              </h2>
+              <p className="text-xs text-muted-foreground">
+                {kindLabels[resourceKind]}
+              </p>
+            </div>
+          </div>
+          <button
+            onClick={onClose}
+            className="p-1.5 rounded-md hover:bg-muted transition-colors duration-150 text-muted-foreground hover:text-foreground"
+            aria-label={tCommon("close")}
+          >
+            <X className="w-5 h-5" />
+          </button>
+        </div>
+
+        <div className="px-6 py-4 space-y-4 overflow-y-auto">
+          <p className="text-sm text-muted-foreground">
+            {t("description")}
+          </p>
+
+          {currentShares.length === 0 && !showAdd && (
+            <div className="text-sm text-muted-foreground italic py-4 text-center">
+              {t("no_shares")}
+            </div>
+          )}
+
+          {currentShares.length > 0 && (
+            <ul className="divide-y divide-border rounded-md border border-border overflow-hidden">
+              {currentShares.map((share) => {
+                const principal = allPrincipalsById.get(share.principalId);
+                return (
+                  <li
+                    key={share.id}
+                    className="flex items-center gap-3 px-3 py-2.5"
+                  >
+                    <Avatar
+                      name={principal?.name}
+                      email={principal?.email ?? undefined}
+                      size="sm"
+                      className="shrink-0"
+                    />
+                    <div className="flex-1 min-w-0">
+                      <div className="text-sm font-medium truncate">
+                        {principal?.name ||
+                          principal?.email ||
+                          share.principalId}
+                      </div>
+                      {principal?.description && (
+                        <div className="text-xs text-muted-foreground truncate">
+                          {principal.description}
+                        </div>
+                      )}
+                    </div>
+                    <div className="relative">
+                      <select
+                        value={share.role}
+                        onChange={(e) =>
+                          handleChangeRole(share.principalId, e.target.value)
+                        }
+                        disabled={savingId === share.principalId}
+                        className="appearance-none rounded-md border border-input bg-background ps-3 pe-8 py-1.5 text-xs focus:outline-none focus:ring-2 focus:ring-ring disabled:opacity-50"
+                      >
+                        {presetOptions.map((p) => (
+                          <option key={p} value={p}>
+                            {t(`preset.${p}`)}
+                          </option>
+                        ))}
+                        {share.role === "custom" && (
+                          <option value="custom">
+                            {t("preset.custom")}
+                          </option>
+                        )}
+                      </select>
+                      <ChevronDown className="w-3 h-3 absolute right-2 top-1/2 -translate-y-1/2 pointer-events-none text-muted-foreground" />
+                    </div>
+                    <button
+                      onClick={() => handleRemove(share.principalId)}
+                      disabled={savingId === share.principalId}
+                      className="p-1.5 rounded-md hover:bg-destructive/10 text-muted-foreground hover:text-destructive transition-colors disabled:opacity-50"
+                      aria-label={t("remove")}
+                      title={t("remove")}
+                    >
+                      {savingId === share.principalId ? (
+                        <Loader2 className="w-4 h-4 animate-spin" />
+                      ) : (
+                        <Trash2 className="w-4 h-4" />
+                      )}
+                    </button>
+                  </li>
+                );
+              })}
+            </ul>
+          )}
+
+          {!showAdd && (
+            <Button
+              variant="outline"
+              onClick={() => setShowAdd(true)}
+              className="w-full"
+            >
+              <UserPlus className="w-4 h-4 me-2" />
+              {t("add_person")}
+            </Button>
+          )}
+
+          {showAdd && (
+            <div className="space-y-2 border border-border rounded-md p-3">
+              <input
+                type="text"
+                value={search}
+                onChange={(e) => setSearch(e.target.value)}
+                placeholder={t("search_placeholder")}
+                className="w-full rounded-md border border-input bg-background px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-ring"
+                autoFocus
+              />
+              <div className="max-h-48 overflow-y-auto -mx-1">
+                {loadingPrincipals && (
+                  <div className="flex items-center justify-center py-4 text-muted-foreground">
+                    <Loader2 className="w-4 h-4 animate-spin me-2" />
+                    {t("loading_principals")}
+                  </div>
+                )}
+                {!loadingPrincipals &&
+                  filteredPrincipals.length === 0 && (
+                    <div className="text-xs text-muted-foreground text-center py-3">
+                      {search.trim()
+                        ? t("no_match")
+                        : t("no_principals")}
+                    </div>
+                  )}
+                {!loadingPrincipals &&
+                  filteredPrincipals.map((p) => (
+                    <button
+                      key={p.id}
+                      onClick={() => handleAdd(p)}
+                      disabled={savingId === p.id}
+                      className="w-full text-start px-3 py-2 rounded-md hover:bg-muted disabled:opacity-50 transition-colors"
+                    >
+                      <div className="flex items-center gap-2">
+                        <Avatar
+                          name={p.name}
+                          email={p.email ?? undefined}
+                          size="sm"
+                          className="shrink-0"
+                        />
+                        <div className="flex-1 min-w-0">
+                          <div className="text-sm font-medium truncate flex items-center gap-2">
+                            {p.name}
+                            {p.type === "group" && (
+                              <span className="text-[10px] uppercase font-normal text-muted-foreground bg-muted rounded px-1 py-0.5">
+                                {t("group")}
+                              </span>
+                            )}
+                          </div>
+                          {p.email && p.email !== p.name && (
+                            <div className="text-xs text-muted-foreground truncate">
+                              {p.email}
+                            </div>
+                          )}
+                        </div>
+                        {savingId === p.id && (
+                          <Loader2 className="w-4 h-4 animate-spin" />
+                        )}
+                      </div>
+                    </button>
+                  ))}
+              </div>
+              <textarea
+                value={message}
+                onChange={(e) => setMessage(e.target.value)}
+                placeholder="Optional message…"
+                rows={2}
+                className="w-full rounded-md border border-input bg-background px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-ring resize-none"
+              />
+              <div className="flex justify-end pt-1">
+                <Button
+                  variant="ghost"
+                  size="sm"
+                  onClick={() => {
+                    setShowAdd(false);
+                    setSearch("");
+                    setMessage("");
+                  }}
+                >
+                  {tCommon("cancel")}
+                </Button>
+              </div>
+            </div>
+          )}
+        </div>
+
+        <div className="flex items-center justify-end gap-2 px-6 py-4 border-t border-border">
+          <Button onClick={onClose}>{tCommon("close")}</Button>
+        </div>
+      </div>
+    </div>
+  );
+}

lib/calendar-freebusy.ts

@@ -0,0 +1,180 @@
+import type { IJMAPClient } from "@/lib/jmap/client-interface";
+import type { CalendarEvent } from "@/lib/jmap/types";
+import { addMinutes } from "date-fns";
+
+export interface FreeBusySlot {
+  start: Date;
+  end: Date;
+  status: "free" | "busy" | "tentative" | "unavailable" | "unknown";
+}
+
+const SLOT_MINUTES = 30;
+
+function clampToSlotStart(d: Date): Date {
+  const clone = new Date(d);
+  clone.setSeconds(0, 0);
+  const mins = clone.getMinutes();
+  const remainder = mins % SLOT_MINUTES;
+  if (remainder !== 0) {
+    clone.setMinutes(mins - remainder, 0, 0);
+  }
+  return clone;
+}
+
+function buildSlots(start: Date, end: Date): FreeBusySlot[] {
+  const slots: FreeBusySlot[] = [];
+  let cursor = new Date(start);
+  while (cursor < end) {
+    const slotEnd = addMinutes(cursor, SLOT_MINUTES);
+    slots.push({
+      start: new Date(cursor),
+      end: slotEnd > end ? new Date(end) : slotEnd,
+      status: "unknown",
+    });
+    cursor = slotEnd;
+  }
+  return slots;
+}
+
+interface EventRange {
+  start: Date;
+  end: Date;
+  freeBusyStatus: CalendarEvent["freeBusyStatus"];
+  eventStatus: CalendarEvent["status"];
+}
+
+function getEventRange(event: CalendarEvent): EventRange {
+  return {
+    start: new Date(event.start),
+    end: new Date(new Date(event.start).getTime() + parseDurationMs(event.duration)),
+    freeBusyStatus: event.freeBusyStatus,
+    eventStatus: event.status,
+  };
+}
+
+function parseDurationMs(duration: string): number {
+  let ms = 0;
+  let sign = 1;
+  let s = duration;
+  if (s.startsWith("-")) {
+    sign = -1;
+    s = s.slice(1);
+  }
+  if (s.startsWith("+")) s = s.slice(1);
+  if (!s.startsWith("P")) return 0;
+  s = s.slice(1);
+  const tIdx = s.indexOf("T");
+  const datePart = tIdx >= 0 ? s.slice(0, tIdx) : s;
+  const timePart = tIdx >= 0 ? s.slice(tIdx + 1) : "";
+
+  let num = "";
+  for (const ch of datePart) {
+    if (ch >= "0" && ch <= "9") {
+      num += ch;
+    } else {
+      const v = parseInt(num, 10) || 0;
+      if (ch === "W") ms += v * 7 * 24 * 60 * 60 * 1000;
+      else if (ch === "D") ms += v * 24 * 60 * 60 * 1000;
+      num = "";
+    }
+  }
+
+  for (const ch of timePart) {
+    if (ch >= "0" && ch <= "9") {
+      num += ch;
+    } else {
+      const v = parseInt(num, 10) || 0;
+      if (ch === "H") ms += v * 60 * 60 * 1000;
+      else if (ch === "M") ms += v * 60 * 1000;
+      else if (ch === "S") ms += v * 1000;
+      num = "";
+    }
+  }
+
+  return ms * sign;
+}
+
+function eventsOverlap(eventStart: Date, eventEnd: Date, slotStart: Date, slotEnd: Date): boolean {
+  return eventStart < slotEnd && eventEnd > slotStart;
+}
+
+function slotStatusFromEvent(
+  event: CalendarEvent,
+  participantStatus: string | null
+): FreeBusySlot["status"] {
+  if (event.status === "cancelled") return "free";
+
+  if (participantStatus === "declined") return "free";
+  if (participantStatus === "tentative") return "tentative";
+
+  if (event.freeBusyStatus === "free") return "free";
+  if (event.freeBusyStatus === "busy") return "busy";
+
+  if (participantStatus === "accepted") return "busy";
+  if (participantStatus === "needs-action") return "tentative";
+
+  return "busy";
+}
+
+export async function fetchFreeBusy(
+  client: IJMAPClient,
+  participants: { email: string }[],
+  start: Date,
+  end: Date
+): Promise<Map<string, FreeBusySlot[]>> {
+  const result = new Map<string, FreeBusySlot[]>();
+
+  const slots = buildSlots(clampToSlotStart(start), end);
+
+  for (const p of participants) {
+    const key = p.email.toLowerCase();
+    const participantSlots: FreeBusySlot[] = slots.map((s) => ({
+      start: new Date(s.start),
+      end: new Date(s.end),
+      status: "unknown" as const,
+    }));
+    result.set(key, participantSlots);
+  }
+
+  try {
+    const events = await client.queryAllCalendarEvents(
+      { after: start.toISOString(), before: end.toISOString() },
+      [{ property: "start", isAscending: true }]
+    );
+
+    for (const event of events) {
+      if (event.status === "cancelled") continue;
+      if (!event.participants) continue;
+
+      const range = getEventRange(event);
+
+      for (const key of result.keys()) {
+        const participant = Object.values(event.participants).find(
+          (p) => p.email.toLowerCase() === key
+        );
+        if (!participant) continue;
+
+        const status = slotStatusFromEvent(event, participant.participationStatus);
+        const participantSlots = result.get(key)!;
+
+        for (const slot of participantSlots) {
+          if (eventsOverlap(range.start, range.end, slot.start, slot.end)) {
+            if (status === "busy" || slot.status === "unknown") {
+              slot.status = status;
+            } else if (status === "tentative" && slot.status === "free") {
+              slot.status = "tentative";
+            }
+          }
+        }
+      }
+    }
+  } catch {
+    // Return unknown statuses for all slots on fetch failure
+  }
+
+  return result;
+}
+
+export function isWorkingHour(hour: number, workStart = 8, workEnd = 18): boolean {
+  return hour >= workStart && hour < workEnd;
+}

lib/contact-csv-import.ts

@@ -0,0 +1,290 @@
+import type { ContactCard, NameComponent } from "@/lib/jmap/types";
+import { generateUUID } from "@/lib/utils";
+
+export interface CsvColumnMapping {
+  firstName: number;
+  lastName: number;
+  email: number;
+  phone: number;
+  company: number;
+  jobTitle: number;
+  address: number;
+  city: number;
+  region: number;
+  postcode: number;
+  country: number;
+  website: number;
+  note: number;
+  nickname: number;
+}
+
+export interface CsvParseResult {
+  headers: string[];
+  rows: string[][];
+  delimiter: string;
+  totalRows: number;
+}
+
+function detectDelimiter(text: string): string {
+  const line = text.split("\n")[0] || "";
+  const counts: Record<string, number> = { ",": 0, ";": 0, "\t": 0 };
+
+  for (const ch of line) {
+    if (ch in counts) counts[ch]++;
+  }
+
+  const best = Object.entries(counts).sort((a, b) => b[1] - a[1])[0];
+  return best && best[1] > 0 ? best[0] : ",";
+}
+
+function parseCsvLine(line: string, delimiter: string): string[] {
+  const fields: string[] = [];
+  let current = "";
+  let inQuotes = false;
+
+  for (let i = 0; i < line.length; i++) {
+    const ch = line[i];
+    if (inQuotes) {
+      if (ch === '"') {
+        if (i + 1 < line.length && line[i + 1] === '"') {
+          current += '"';
+          i++;
+        } else {
+          inQuotes = false;
+        }
+      } else {
+        current += ch;
+      }
+    } else if (ch === '"') {
+      inQuotes = true;
+    } else if (ch === delimiter) {
+      fields.push(current.trim());
+      current = "";
+    } else {
+      current += ch;
+    }
+  }
+  fields.push(current.trim());
+
+  return fields;
+}
+
+export function parseCSV(text: string): CsvParseResult {
+  const delimiter = detectDelimiter(text);
+  const rawLines = text.split(/\r?\n/);
+
+  const headers = parseCsvLine(rawLines[0] || "", delimiter);
+  const rows: string[][] = [];
+
+  for (let i = 1; i < rawLines.length; i++) {
+    const line = rawLines[i].trim();
+    if (!line) continue;
+    const fields = parseCsvLine(line, delimiter);
+    if (fields.length > 0 && fields.some((f) => f.length > 0)) {
+      rows.push(fields);
+    }
+  }
+
+  return { headers, rows, delimiter, totalRows: rows.length };
+}
+
+const NAME_PATTERNS = [
+  /^(?:first[\s_-]?name|given[\s_-]?name|forename|vorname|prénom|nombre|名)$/i,
+];
+const LAST_NAME_PATTERNS = [
+  /^(?:last[\s_-]?name|surname|family[\s_-]?name|nachname|nom|姓)$/i,
+];
+const EMAIL_PATTERNS = [
+  /^(?:e?-?mail|email[\s_-]?address|e?-?mail[\s_-]?address|e-mail-adresse)$/i,
+];
+const PHONE_PATTERNS = [
+  /^(?:phone|telephone|tel|mobile|cell|handy|telefon|téléphone|电话)$/i,
+];
+const COMPANY_PATTERNS = [
+  /^(?:company|organization|org|firma|unternehmen|entreprise|société|公司)$/i,
+];
+const JOB_TITLE_PATTERNS = [
+  /^(?:job[\s_-]?title|title|position|role|funktion|beruf|poste)$/i,
+];
+const ADDRESS_PATTERNS = [
+  /^(?:address|addr|street|straße|adresse|rue)$/i,
+];
+const CITY_PATTERNS = [
+  /^(?:city|town|ort|stadt|ville)$/i,
+];
+const REGION_PATTERNS = [
+  /^(?:state|province|region|bundesland|région)$/i,
+];
+const POSTCODE_PATTERNS = [
+  /^(?:zip|postal[\s_-]?code|postcode|plz|code[\s_-]?postal)$/i,
+];
+const COUNTRY_PATTERNS = [
+  /^(?:country|land|pays)$/i,
+];
+const WEBSITE_PATTERNS = [
+  /^(?:website|url|web|homepage|site)$/i,
+];
+const NOTE_PATTERNS = [
+  /^(?:note|notes|comments|bemerkung|notiz|remarque)$/i,
+];
+const NICKNAME_PATTERNS = [
+  /^(?:nickname|nick|alias|spitzname|surnom)$/i,
+];
+
+function findColumnIndex(headers: string[], patterns: RegExp[]): number {
+  for (const pattern of patterns) {
+    const idx = headers.findIndex((h) => pattern.test(h));
+    if (idx >= 0) return idx;
+  }
+  return -1;
+}
+
+export function autoMapColumns(headers: string[]): CsvColumnMapping {
+  return {
+    firstName: findColumnIndex(headers, NAME_PATTERNS),
+    lastName: findColumnIndex(headers, LAST_NAME_PATTERNS),
+    email: findColumnIndex(headers, EMAIL_PATTERNS),
+    phone: findColumnIndex(headers, PHONE_PATTERNS),
+    company: findColumnIndex(headers, COMPANY_PATTERNS),
+    jobTitle: findColumnIndex(headers, JOB_TITLE_PATTERNS),
+    address: findColumnIndex(headers, ADDRESS_PATTERNS),
+    city: findColumnIndex(headers, CITY_PATTERNS),
+    region: findColumnIndex(headers, REGION_PATTERNS),
+    postcode: findColumnIndex(headers, POSTCODE_PATTERNS),
+    country: findColumnIndex(headers, COUNTRY_PATTERNS),
+    website: findColumnIndex(headers, WEBSITE_PATTERNS),
+    note: findColumnIndex(headers, NOTE_PATTERNS),
+    nickname: findColumnIndex(headers, NICKNAME_PATTERNS),
+  };
+}
+
+function getCol(row: string[], colIndex: number): string {
+  if (colIndex < 0 || colIndex >= row.length) return "";
+  return row[colIndex]?.trim() || "";
+}
+
+export function mapRowToContact(
+  row: string[],
+  mapping: CsvColumnMapping,
+  addressBookIds: Record<string, boolean>,
+): ContactCard | null {
+  const id = `import-csv-${generateUUID()}`;
+
+  const firstName = getCol(row, mapping.firstName);
+  const lastName = getCol(row, mapping.lastName);
+  const email = getCol(row, mapping.email);
+  const phone = getCol(row, mapping.phone);
+  const company = getCol(row, mapping.company);
+  const jobTitle = getCol(row, mapping.jobTitle);
+  const address = getCol(row, mapping.address);
+  const city = getCol(row, mapping.city);
+  const region = getCol(row, mapping.region);
+  const postcode = getCol(row, mapping.postcode);
+  const country = getCol(row, mapping.country);
+  const website = getCol(row, mapping.website);
+  const note = getCol(row, mapping.note);
+  const nickname = getCol(row, mapping.nickname);
+
+  if (!email && !firstName && !lastName) return null;
+
+  const components: NameComponent[] = [];
+  if (firstName) components.push({ kind: "given", value: firstName });
+  if (lastName) components.push({ kind: "surname", value: lastName });
+
+  const contact: ContactCard = {
+    id,
+    addressBookIds,
+  };
+
+  if (components.length > 0) {
+    contact.name = { components, isOrdered: true };
+  } else if (email) {
+    contact.name = { full: email.split("@")[0] };
+  }
+
+  if (email) {
+    contact.emails = {
+      e0: { address: email },
+    };
+  }
+
+  if (phone) {
+    contact.phones = {
+      p0: { number: phone },
+    };
+  }
+
+  if (company) {
+    contact.organizations = {
+      o0: { name: company },
+    };
+  }
+
+  if (jobTitle) {
+    contact.titles = {
+      t0: { name: jobTitle, kind: "title" },
+    };
+  }
+
+  if (address || city || region || postcode || country) {
+    contact.addresses = {
+      a0: {
+        street: address || undefined,
+        locality: city || undefined,
+        region: region || undefined,
+        postcode: postcode || undefined,
+        country: country || undefined,
+      },
+    };
+  }
+
+  if (website) {
+    contact.onlineServices = {
+      u0: { uri: website },
+    };
+  }
+
+  if (note) {
+    contact.notes = {
+      n0: { note },
+    };
+  }
+
+  if (nickname) {
+    contact.nicknames = {
+      n0: { name: nickname },
+    };
+  }
+
+  return contact;
+}
+
+export function detectDuplicatesByEmail(
+  existingContacts: ContactCard[],
+  incoming: ContactCard[],
+): Map<number, string> {
+  const dupes = new Map<number, string>();
+  const existingEmails = new Map<string, string>();
+
+  for (const c of existingContacts) {
+    if (c.emails) {
+      for (const e of Object.values(c.emails)) {
+        existingEmails.set(e.address.toLowerCase(), c.id);
+      }
+    }
+  }
+
+  incoming.forEach((card, idx) => {
+    if (card.emails) {
+      for (const e of Object.values(card.emails)) {
+        const match = existingEmails.get(e.address.toLowerCase());
+        if (match) {
+          dupes.set(idx, match);
+          return;
+        }
+      }
+    }
+  });
+
+  return dupes;
+}

lib/demo/demo-client.ts

@@ -1037,6 +1037,8 @@ export class DemoJMAPClient implements IJMAPClient {
     return [...this.data.fileNodes];
   }
 
+  async setMailboxShare(): Promise<void> { /* demo: no-op */ }
+
   async setFileNodeShare(): Promise<void> { /* demo: no-op */ }
 
   async getFileNodes(ids: string[] | null): Promise<FileNode[]> {

lib/email-import.ts

@@ -0,0 +1,249 @@
+import type { IJMAPClient } from "@/lib/jmap/client-interface";
+import type { Mailbox } from "@/lib/jmap/types";
+import { expandImportableEmails } from "@/lib/eml-import";
+
+export type ConflictResolution = "skip" | "replace" | "copy";
+
+export interface ImportProgress {
+  total: number;
+  processed: number;
+  imported: number;
+  skipped: number;
+  failed: number;
+  currentFile: string;
+}
+
+export interface ImportResult {
+  imported: number;
+  skipped: number;
+  failed: number;
+  errors: Array<{ file: string; error: string }>;
+}
+
+function toBase64(buffer: ArrayBuffer): string {
+  let binary = "";
+  const bytes = new Uint8Array(buffer);
+  for (let i = 0; i < bytes.byteLength; i++) {
+    binary += String.fromCharCode(bytes[i]);
+  }
+  return btoa(binary);
+}
+
+interface ParsedEml {
+  messageId: string | null;
+  subject: string;
+  from: string;
+  to: string;
+  cc: string;
+  date: string;
+  bodyPlain: string;
+  bodyHtml: string;
+  raw: Blob;
+}
+
+async function parseEml(file: Blob): Promise<ParsedEml> {
+  const { default: PostalMime } = await import("postal-mime");
+  const buffer = await file.arrayBuffer();
+  const parsed = await PostalMime.parse(buffer);
+
+  return {
+    messageId: (parsed.messageId || null) as string | null,
+    subject: parsed.subject || "(No Subject)",
+    from: typeof parsed.from === "object" && parsed.from?.address
+      ? `${parsed.from.name || ""} <${parsed.from.address}>`.trim()
+      : String(parsed.from || ""),
+    to: Array.isArray(parsed.to)
+      ? parsed.to.map((r: { address?: string; name?: string }) =>
+          r.name ? `${r.name} <${r.address}>` : r.address || ""
+        ).join(", ")
+      : "",
+    cc: Array.isArray(parsed.cc)
+      ? parsed.cc.map((r: { address?: string; name?: string }) =>
+          r.name ? `${r.name} <${r.address}>` : r.address || ""
+        ).join(", ")
+      : "",
+    date: parsed.date || "",
+    bodyPlain: parsed.text || "",
+    bodyHtml: parsed.html || "",
+    raw: file,
+  };
+}
+
+async function findExistingMessageIds(
+  client: IJMAPClient,
+  messageIds: string[],
+): Promise<Set<string>> {
+  const existing = new Set<string>();
+  const batchSize = 50;
+
+  for (let i = 0; i < messageIds.length; i += batchSize) {
+    const batch = messageIds.slice(i, i + batchSize);
+    try {
+      const conditions = batch.map((id) => ({
+        header: ["Message-ID", `<${id}>`] as [string, string],
+      }));
+
+      const filter = conditions.length === 1
+        ? conditions[0]
+        : { operator: "OR", conditions };
+
+      const { emails } = await client.advancedSearchEmails(filter, undefined, batchSize);
+      for (const email of emails) {
+        if (email.messageId && batch.includes(email.messageId)) {
+          existing.add(email.messageId);
+        }
+      }
+    } catch {
+      // best-effort dedup lookup
+    }
+  }
+
+  return existing;
+}
+
+function generateRfc822FromParsed(eml: ParsedEml): Blob {
+  const lines: string[] = [];
+  lines.push(`From: ${eml.from}`);
+  if (eml.to) lines.push(`To: ${eml.to}`);
+  if (eml.cc) lines.push(`Cc: ${eml.cc}`);
+  if (eml.messageId) lines.push(`Message-ID: <${eml.messageId}>`);
+  lines.push(`Date: ${eml.date || new Date().toUTCString()}`);
+  lines.push(`Subject: ${eml.subject}`);
+  lines.push("MIME-Version: 1.0");
+
+  if (eml.bodyHtml) {
+    const boundary = `----=_Boundary_${Date.now().toString(36)}`;
+    lines.push(`Content-Type: multipart/alternative; boundary="${boundary}"`);
+    lines.push("");
+    lines.push(`--${boundary}`);
+    lines.push("Content-Type: text/plain; charset=utf-8");
+    lines.push("Content-Transfer-Encoding: quoted-printable");
+    lines.push("");
+    lines.push(eml.bodyPlain);
+    lines.push(`--${boundary}`);
+    lines.push("Content-Type: text/html; charset=utf-8");
+    lines.push("Content-Transfer-Encoding: quoted-printable");
+    lines.push("");
+    lines.push(eml.bodyHtml);
+    lines.push(`--${boundary}--`);
+  } else {
+    lines.push("Content-Type: text/plain; charset=utf-8");
+    lines.push("Content-Transfer-Encoding: quoted-printable");
+    lines.push("");
+    lines.push(eml.bodyPlain);
+  }
+
+  return new Blob([lines.join("\r\n")], { type: "message/rfc822" });
+}
+
+async function extractMessageIdFromEml(blob: Blob): Promise<string | null> {
+  try {
+    const text = await blob.text();
+    const match = text.match(/^Message-ID:\s*(.+)$/im);
+    if (match) {
+      return match[1].trim().replace(/^<+/, "").replace(/>+$/, "");
+    }
+  } catch {
+    // best-effort message-id extraction
+  }
+  return null;
+}
+
+export async function importEmails({
+  client,
+  files,
+  destinationMailboxId,
+  conflictResolution,
+  onProgress,
+  signal,
+}: {
+  client: IJMAPClient;
+  files: File[];
+  destinationMailboxId: string;
+  conflictResolution: ConflictResolution;
+  onProgress?: (progress: ImportProgress) => void;
+  signal?: AbortSignal;
+}): Promise<ImportResult> {
+  const result: ImportResult = { imported: 0, skipped: 0, failed: 0, errors: [] };
+  const progress: ImportProgress = {
+    total: 0,
+    processed: 0,
+    imported: 0,
+    skipped: 0,
+    failed: 0,
+    currentFile: "",
+  };
+
+  const importables = await expandImportableEmails(files);
+  progress.total = importables.length;
+  onProgress?.({ ...progress });
+
+  if (importables.length === 0) {
+    return result;
+  }
+
+  const duplicateCheck = conflictResolution !== "copy";
+  let existingMessageIds: Set<string> | null = null;
+
+  if (duplicateCheck) {
+    const messageIds: string[] = [];
+    for (const item of importables) {
+      if (signal?.aborted) break;
+      const msgId = await extractMessageIdFromEml(item.blob);
+      if (msgId) messageIds.push(msgId);
+    }
+    existingMessageIds = await findExistingMessageIds(client, messageIds);
+  }
+
+  for (const item of importables) {
+    if (signal?.aborted) break;
+
+    progress.currentFile = item.name;
+    progress.processed++;
+    onProgress?.({ ...progress });
+
+    try {
+      const msgId = await extractMessageIdFromEml(item.blob);
+      if (duplicateCheck && msgId && existingMessageIds?.has(msgId)) {
+        if (conflictResolution === "skip") {
+          progress.skipped++;
+          result.skipped++;
+          onProgress?.({ ...progress });
+          continue;
+        }
+      }
+
+      let emlBlob = item.blob;
+
+      try {
+        const parsed = await parseEml(item.blob);
+        emlBlob = generateRfc822FromParsed(parsed);
+      } catch {
+      // best-effort dedup lookup
+      }
+
+      const file = new File([emlBlob], item.name, { type: "message/rfc822" });
+      const { blobId } = await client.uploadBlob(file);
+
+      await client.importEmail(
+        blobId,
+        { [destinationMailboxId]: true },
+        { "$seen": true },
+      );
+
+      progress.imported++;
+      result.imported++;
+    } catch (err) {
+      progress.failed++;
+      result.failed++;
+      result.errors.push({
+        file: item.name,
+        error: err instanceof Error ? err.message : "Unknown error",
+      });
+    }
+
+    onProgress?.({ ...progress });
+  }
+
+  return result;
+}

lib/eml-import.ts

@@ -13,6 +13,14 @@ function isZipName(name: string): boolean {
   return /\.zip$/i.test(name);
 }
 
+function isTgzName(name: string): boolean {
+  return /\.(tgz|tar\.gz)$/i.test(name);
+}
+
+function isArchiveName(name: string): boolean {
+  return isZipName(name) || isTgzName(name);
+}
+
 async function extractEmlsFromZip(file: File): Promise<ImportableEmail[]> {
   const { default: JSZip } = await import("jszip");
   const zip = await JSZip.loadAsync(await file.arrayBuffer());
@@ -30,6 +38,88 @@ async function extractEmlsFromZip(file: File): Promise<ImportableEmail[]> {
   return out;
 }
 
+async function gunzip(buffer: ArrayBuffer): Promise<ArrayBuffer> {
+  try {
+    const ds = new DecompressionStream("gzip");
+    const writer = ds.writable.getWriter();
+    const reader = ds.readable.getReader();
+
+    writer.write(new Uint8Array(buffer));
+    writer.close();
+
+    const chunks: Uint8Array[] = [];
+    while (true) {
+      const { done, value } = await reader.read();
+      if (done) break;
+      chunks.push(value);
+    }
+
+    const totalLength = chunks.reduce((sum, c) => sum + c.length, 0);
+    const result = new Uint8Array(totalLength);
+    let offset = 0;
+    for (const chunk of chunks) {
+      result.set(chunk, offset);
+      offset += chunk.length;
+    }
+    return result.buffer;
+  } catch {
+    throw new Error("Failed to decompress gzip archive");
+  }
+}
+
+interface TarEntry {
+  name: string;
+  type: string;
+  data: ArrayBuffer;
+}
+
+function parseTar(buffer: ArrayBuffer): TarEntry[] {
+  const entries: TarEntry[] = [];
+  const view = new Uint8Array(buffer);
+  let offset = 0;
+
+  while (offset + 512 <= view.byteLength) {
+    const header = new Uint8Array(buffer, offset, 512);
+    const name = new TextDecoder().decode(header.subarray(0, 100)).replace(/\0.*$/, "");
+    const type = String.fromCharCode(header[156] || 0) || "0";
+
+    if (!name) break;
+
+    let sizeStr = "";
+    for (let i = 124; i < 136; i++) {
+      const ch = String.fromCharCode(header[i]);
+      if (ch === "\0" || ch === " ") break;
+      sizeStr += ch;
+    }
+    const size = parseInt(sizeStr || "0", 8);
+
+    offset += 512;
+
+    if (size > 0 && type === "0" && isEmlName(name)) {
+      const data = buffer.slice(offset, offset + size);
+      entries.push({
+        name: name.split(/[\\/]/).pop() || name,
+        type: "file",
+        data,
+      });
+    }
+
+    offset += Math.ceil(size / 512) * 512;
+  }
+
+  return entries;
+}
+
+async function extractEmlsFromTgz(file: File): Promise<ImportableEmail[]> {
+  const buffer = await file.arrayBuffer();
+  const decompressed = await gunzip(buffer);
+  const entries = parseTar(decompressed);
+  return entries.map((entry) => ({
+    name: entry.name,
+    blob: new Blob([entry.data], { type: EMAIL_MIME }),
+  }));
+}
+
 export async function expandImportableEmails(
   files: File[],
 ): Promise<ImportableEmail[]> {
@@ -39,10 +129,14 @@ export async function expandImportableEmails(
       out.push(...(await extractEmlsFromZip(file)));
       continue;
     }
+    if (isTgzName(file.name) || file.type === "application/gzip" || file.type === "application/x-gtar") {
+      out.push(...(await extractEmlsFromTgz(file)));
+      continue;
+    }
     const blob = new Blob([await file.arrayBuffer()], { type: EMAIL_MIME });
     out.push({ name: file.name, blob });
   }
   return out;
 }
 
-export const EML_IMPORT_ACCEPT = ".eml,.zip,message/rfc822,application/zip";
+export const EML_IMPORT_ACCEPT = ".eml,.zip,.tgz,.tar.gz,message/rfc822,application/zip,application/gzip";

lib/jmap/client-interface.ts

@@ -1,4 +1,4 @@
-import type { Email, Mailbox, StateChange, AccountStates, Thread, Identity, EmailAddress, ContactCard, AddressBook, AddressBookRights, VacationResponse, Calendar, CalendarRights, CalendarEvent, CalendarEventFilter, CalendarTask, FileNode, FileNodeRights, Principal, PushSubscription, ScheduledEmail, SendEmailResult, SharedAccount } from "./types";
+import type { Email, Mailbox, MailboxRights, StateChange, AccountStates, Thread, Identity, EmailAddress, ContactCard, AddressBook, AddressBookRights, VacationResponse, Calendar, CalendarRights, CalendarEvent, CalendarEventFilter, CalendarTask, FileNode, FileNodeRights, Principal, PushSubscription, ScheduledEmail, SendEmailResult, SharedAccount } from "./types";
 import type { SieveScript, SieveCapabilities } from "./sieve-types";
 
 /**
@@ -315,6 +315,7 @@ export interface IJMAPClient {
   setCalendarShare(calendarId: string, principalId: string, rights: CalendarRights | null, targetAccountId?: string): Promise<void>;
   setAddressBookShare(addressBookId: string, principalId: string, rights: AddressBookRights | null, targetAccountId?: string): Promise<void>;
   setFileNodeShare(fileNodeId: string, principalId: string, rights: FileNodeRights | null, targetAccountId?: string): Promise<void>;
+  setMailboxShare(mailboxId: string, principalId: string, rights: MailboxRights | null, targetAccountId?: string): Promise<void>;
 
   // ── Accounts (primary + shared/group) ────────────────────────
   getSharedAccounts(): SharedAccount[];

lib/jmap/client.ts

@@ -1,4 +1,4 @@
-import type { Email, Mailbox, StateChange, AccountStates, Thread, Identity, EmailAddress, ContactCard, AddressBook, AddressBookRights, VacationResponse, Calendar, CalendarRights, CalendarEvent, CalendarEventFilter, CalendarTask, FileNode, FileNodeFilter, FileNodeRights, Principal, PushSubscription, EmailSubmission, ScheduledEmail, SendEmailResult, SharedAccount } from "./types";
+import type { Email, Mailbox, MailboxRights, StateChange, AccountStates, Thread, Identity, EmailAddress, ContactCard, AddressBook, AddressBookRights, VacationResponse, Calendar, CalendarRights, CalendarEvent, CalendarEventFilter, CalendarTask, FileNode, FileNodeFilter, FileNodeRights, Principal, PushSubscription, EmailSubmission, ScheduledEmail, SendEmailResult, SharedAccount } from "./types";
 import type { SieveScript, SieveCapabilities } from "./sieve-types";
 import type { IJMAPClient } from "./client-interface";
 import { toWildcardQuery } from "./search-utils";
@@ -4426,6 +4426,34 @@ export class JMAPClient implements IJMAPClient {
     }
   }
 
+  /**
+   * Add, update, or remove a principal's rights on a mailbox folder.
+   * Pass `rights: null` to revoke access.
+   */
+  async setMailboxShare(
+    mailboxId: string,
+    principalId: string,
+    rights: MailboxRights | null,
+    targetAccountId?: string,
+  ): Promise<void> {
+    const accountId = targetAccountId || this.accountId;
+    const response = await this.request([
+      ["Mailbox/set", {
+        accountId,
+        update: { [mailboxId]: { [`shareWith/${principalId}`]: rights } },
+      }, "0"],
+    ]);
+
+    const result = response.methodResponses?.[0]?.[1];
+    if (result?.notUpdated?.[mailboxId]) {
+      const err = result.notUpdated[mailboxId];
+      throw new Error(err.description || "Failed to update mailbox share");
+    }
+    if (!result?.updated || !(mailboxId in result.updated)) {
+      throw new Error("Server did not confirm the share update");
+    }
+  }
+
   private async fetchPaginatedContacts(
     accountId: string,
     filter?: Record<string, unknown>,

lib/jmap/types.ts

@@ -181,6 +181,19 @@ export interface Attachment {
   disposition?: string;
 }
 
+export interface MailboxRights {
+  mayReadItems: boolean;
+  mayAddItems: boolean;
+  mayRemoveItems: boolean;
+  maySetSeen: boolean;
+  maySetKeywords: boolean;
+  mayCreateChild: boolean;
+  mayRename: boolean;
+  mayDelete: boolean;
+  maySubmit: boolean;
+  mayShare?: boolean;
+}
+
 export interface Mailbox {
   id: string;
   originalId?: string; // Original JMAP ID (for shared mailboxes)
@@ -192,22 +205,13 @@ export interface Mailbox {
   unreadEmails: number;
   totalThreads: number;
   unreadThreads: number;
-  myRights: {
+  myRights: MailboxRights;
-    mayReadItems: boolean;
-    mayAddItems: boolean;
-    mayRemoveItems: boolean;
-    maySetSeen: boolean;
-    maySetKeywords: boolean;
-    mayCreateChild: boolean;
-    mayRename: boolean;
-    mayDelete: boolean;
-    maySubmit: boolean;
-  };
   isSubscribed: boolean;
   // Shared folder support
   accountId?: string;
   accountName?: string;
   isShared?: boolean;
+  shareWith?: Record<string, MailboxRights> | null;
 }
 
 export interface Thread {

locales/en/common.json

@@ -892,6 +892,8 @@
       "downloads": "Downloads",
       "content_senders": "Content & Senders",
       "about_data": "About & Data",
+      "import": "Import",
+      "sharing": "Sharing",
       "debug": "Debug"
     },
     "tab_groups": {
@@ -2057,6 +2059,7 @@
     "new_subfolder": "New subfolder...",
     "new_folder": "New folder...",
     "rename": "Rename...",
+    "share_folder": "Share Folder...",
     "import_email": "Import .eml or .zip...",
     "empty_folder": "Empty folder",
     "empty_folder_generic": "Empty folder",
@@ -2662,6 +2665,20 @@
       "no_participants": "No participants",
       "count": "{count, plural, one {# participant} other {# participants}}"
     },
+    "freeBusy": {
+      "title": "Availability",
+      "check": "Check Availability",
+      "hide": "Hide Availability",
+      "loading": "Loading...",
+      "no_participants": "Add participants to check availability.",
+      "timezone": "Timezone",
+      "free": "Free",
+      "busy": "Busy",
+      "tentative": "Tentative",
+      "unavailable": "Out of office",
+      "unknown": "No information",
+      "click_to_select": "Click a free slot to select this time"
+    },
     "recurrence": {
       "title": "Recurrence",
       "none": "Does not repeat",
@@ -3012,7 +3029,14 @@
       "readWrite": "Read & write",
       "manager": "Manager",
       "custom": "Custom"
-    }
+    },
+    "tab_shared_by_me": "Shared by me",
+    "tab_shared_with_me": "Shared with me",
+    "no_shares_by_me": "You haven't shared anything yet.",
+    "no_shares_with_me": "No folders shared with you yet.",
+    "shared_by": "Shared by",
+    "accept": "Accept",
+    "decline": "Decline"
   },
   "advanced_search": {
     "title": "Advanced Search",

stores/sharing-store.ts

@@ -0,0 +1,523 @@
+import { create } from "zustand";
+import type { IJMAPClient } from "@/lib/jmap/client-interface";
+import type {
+  Principal,
+  CalendarRights,
+  AddressBookRights,
+  FileNodeRights,
+  MailboxRights,
+} from "@/lib/jmap/types";
+import { toast } from "@/stores/toast-store";
+
+export type SharedResourceKind =
+  | "mailbox"
+  | "calendar"
+  | "addressBook"
+  | "file";
+
+export interface SharedFolder {
+  id: string;
+  resourceId: string;
+  resourceName: string;
+  resourceKind: SharedResourceKind;
+  principalId: string;
+  principalName: string;
+  principalEmail: string | null;
+  role: string;
+  direction: "byMe" | "withMe";
+  pending: boolean;
+  accountId?: string;
+}
+
+interface SharingState {
+  sharedByMe: SharedFolder[];
+  sharedWithMe: SharedFolder[];
+  loading: boolean;
+  principalsCache: Principal[];
+
+  loadPrincipals: (client: IJMAPClient) => Promise<Principal[]>;
+  fetchShares: (client: IJMAPClient) => Promise<void>;
+  shareFolder: (
+    client: IJMAPClient,
+    resourceId: string,
+    resourceName: string,
+    resourceKind: SharedResourceKind,
+    principalId: string,
+    role: string,
+    message?: string,
+    accountId?: string,
+  ) => Promise<void>;
+  revokeShare: (
+    client: IJMAPClient,
+    resourceId: string,
+    resourceKind: SharedResourceKind,
+    principalId: string,
+    accountId?: string,
+  ) => Promise<void>;
+  changeRole: (
+    client: IJMAPClient,
+    resourceId: string,
+    resourceKind: SharedResourceKind,
+    principalId: string,
+    role: string,
+    accountId?: string,
+  ) => Promise<void>;
+  acceptShare: (client: IJMAPClient, share: SharedFolder) => Promise<void>;
+  declineShare: (client: IJMAPClient, share: SharedFolder) => Promise<void>;
+}
+
+function roleLabel(kind: SharedResourceKind, role: string): string {
+  if (kind === "mailbox") return MAILBOX_ROLE_LABELS[role] ?? role;
+  return role;
+}
+
+const MAILBOX_PRESETS: Record<string, MailboxRights> = {
+  read: {
+    mayReadItems: true,
+    mayAddItems: false,
+    mayRemoveItems: false,
+    maySetSeen: false,
+    maySetKeywords: false,
+    mayCreateChild: false,
+    mayRename: false,
+    mayDelete: false,
+    maySubmit: false,
+  },
+  readWrite: {
+    mayReadItems: true,
+    mayAddItems: true,
+    mayRemoveItems: false,
+    maySetSeen: true,
+    maySetKeywords: true,
+    mayCreateChild: false,
+    mayRename: false,
+    mayDelete: false,
+    maySubmit: true,
+  },
+  manager: {
+    mayReadItems: true,
+    mayAddItems: true,
+    mayRemoveItems: true,
+    maySetSeen: true,
+    maySetKeywords: true,
+    mayCreateChild: true,
+    mayRename: true,
+    mayDelete: true,
+    maySubmit: true,
+    mayShare: true,
+  },
+};
+
+const MAILBOX_ROLE_LABELS: Record<string, string> = {
+  read: "Viewer",
+  readWrite: "Editor",
+  manager: "Manager",
+};
+
+const CALENDAR_PRESETS: Record<string, CalendarRights> = {
+  read: {
+    mayReadFreeBusy: true,
+    mayReadItems: true,
+    mayWriteAll: false,
+    mayWriteOwn: false,
+    mayUpdatePrivate: false,
+    mayRSVP: false,
+    mayShare: false,
+    mayDelete: false,
+  },
+  readWrite: {
+    mayReadFreeBusy: true,
+    mayReadItems: true,
+    mayWriteAll: true,
+    mayWriteOwn: true,
+    mayUpdatePrivate: true,
+    mayRSVP: true,
+    mayShare: false,
+    mayDelete: false,
+  },
+  manager: {
+    mayReadFreeBusy: true,
+    mayReadItems: true,
+    mayWriteAll: true,
+    mayWriteOwn: true,
+    mayUpdatePrivate: true,
+    mayRSVP: true,
+    mayShare: true,
+    mayDelete: true,
+  },
+};
+
+const ADDRESS_BOOK_PRESETS: Record<string, AddressBookRights> = {
+  read: { mayRead: true, mayWrite: false, mayShare: false, mayDelete: false },
+  readWrite: {
+    mayRead: true,
+    mayWrite: true,
+    mayShare: false,
+    mayDelete: false,
+  },
+  manager: {
+    mayRead: true,
+    mayWrite: true,
+    mayShare: true,
+    mayDelete: true,
+  },
+};
+
+const FILE_PRESETS: Record<string, FileNodeRights> = {
+  read: {
+    mayRead: true,
+    mayAddChildren: false,
+    mayRename: false,
+    mayDelete: false,
+    mayModifyContent: false,
+    mayShare: false,
+  },
+  readWrite: {
+    mayRead: true,
+    mayAddChildren: true,
+    mayRename: true,
+    mayDelete: true,
+    mayModifyContent: true,
+    mayShare: false,
+  },
+  manager: {
+    mayRead: true,
+    mayAddChildren: true,
+    mayRename: true,
+    mayDelete: true,
+    mayModifyContent: true,
+    mayShare: true,
+  },
+};
+
+function resolveRights(
+  kind: SharedResourceKind,
+  role: string,
+): MailboxRights | CalendarRights | AddressBookRights | FileNodeRights {
+  switch (kind) {
+    case "mailbox":
+      return (
+        MAILBOX_PRESETS[role] ?? MAILBOX_PRESETS.read
+      );
+    case "calendar":
+      return (
+        CALENDAR_PRESETS[role] ?? CALENDAR_PRESETS.read
+      );
+    case "addressBook":
+      return (
+        ADDRESS_BOOK_PRESETS[role] ?? ADDRESS_BOOK_PRESETS.read
+      );
+    case "file":
+      return FILE_PRESETS[role] ?? FILE_PRESETS.read;
+  }
+}
+
+export const useSharingStore = create<SharingState>((set, get) => ({
+  sharedByMe: [],
+  sharedWithMe: [],
+  loading: false,
+  principalsCache: [],
+
+  async loadPrincipals(client) {
+    const cached = get().principalsCache;
+    if (cached.length > 0) return cached;
+    const principals = await client.getPrincipals();
+    set({ principalsCache: principals });
+    return principals;
+  },
+
+  async fetchShares(client) {
+    set({ loading: true });
+    try {
+      const principals = await client.getPrincipals();
+      const principalMap = new Map<string, Principal>();
+      for (const p of principals) principalMap.set(p.id, p);
+
+      const byMe: SharedFolder[] = [];
+      const withMe: SharedFolder[] = [];
+
+      try {
+        const mailboxes = await client.getAllMailboxes();
+        for (const mb of mailboxes) {
+          const shares = mb.shareWith;
+          if (shares && Object.keys(shares).length > 0) {
+            for (const [principalId, rights] of Object.entries(shares)) {
+              const p = principalMap.get(principalId);
+              byMe.push({
+                id: `mb-${mb.id}-${principalId}`,
+                resourceId: mb.id,
+                resourceName: mb.name,
+                resourceKind: "mailbox",
+                principalId,
+                principalName: p?.name ?? principalId,
+                principalEmail: p?.email ?? null,
+                role: roleLabel("mailbox", detectMailboxPreset(rights)),
+                direction: "byMe",
+                pending: false,
+                accountId: mb.accountId,
+              });
+            }
+          }
+        }
+      } catch {
+        /* mailboxes may not be available */
+      }
+
+      try {
+        if (client.supportsCalendars()) {
+          const calendars = await client.getAllCalendars();
+          for (const cal of calendars) {
+            const shares = cal.shareWith;
+            if (shares && Object.keys(shares).length > 0) {
+              for (const [principalId, rights] of Object.entries(shares)) {
+                const p = principalMap.get(principalId);
+                byMe.push({
+                  id: `cal-${cal.id}-${principalId}`,
+                  resourceId: cal.id,
+                  resourceName: cal.name,
+                  resourceKind: "calendar",
+                  principalId,
+                  principalName: p?.name ?? principalId,
+                  principalEmail: p?.email ?? null,
+                  role: roleLabel("calendar", detectCalendarPreset(rights)),
+                  direction: "byMe",
+                  pending: false,
+                  accountId: cal.accountId,
+                });
+              }
+            }
+          }
+        }
+      } catch {
+        /* calendars may not be available */
+      }
+
+      try {
+        if (client.supportsContacts()) {
+          const books = await client.getAllAddressBooks();
+          for (const book of books) {
+            const shares = book.shareWith;
+            if (shares && Object.keys(shares).length > 0) {
+              for (const [principalId, rights] of Object.entries(shares)) {
+                const p = principalMap.get(principalId);
+                byMe.push({
+                  id: `ab-${book.id}-${principalId}`,
+                  resourceId: book.id,
+                  resourceName: book.name,
+                  resourceKind: "addressBook",
+                  principalId,
+                  principalName: p?.name ?? principalId,
+                  principalEmail: p?.email ?? null,
+                  role: roleLabel(
+                    "addressBook",
+                    detectAddressBookPreset(rights),
+                  ),
+                  direction: "byMe",
+                  pending: false,
+                  accountId: book.accountId,
+                });
+              }
+            }
+          }
+        }
+      } catch {
+        /* address books may not be available */
+      }
+
+      set({ sharedByMe: byMe, sharedWithMe: withMe, loading: false, principalsCache: principals });
+    } catch {
+      set({ loading: false });
+    }
+  },
+
+  async shareFolder(
+    client,
+    resourceId,
+    resourceName,
+    resourceKind,
+    principalId,
+    role,
+    _message,
+    accountId,
+  ) {
+    const rights = resolveRights(resourceKind, role);
+    await applyShare(client, resourceKind, resourceId, principalId, rights, accountId);
+
+    const princ = get().principalsCache.find((p) => p.id === principalId);
+    const entry: SharedFolder = {
+      id: `${resourceKind}-${resourceId}-${principalId}`,
+      resourceId,
+      resourceName,
+      resourceKind,
+      principalId,
+      principalName: princ?.name ?? principalId,
+      principalEmail: princ?.email ?? null,
+      role,
+      direction: "byMe",
+      pending: false,
+      accountId,
+    };
+
+    set((s) => ({
+      sharedByMe: [
+        ...s.sharedByMe.filter(
+          (f) =>
+            !(
+              f.resourceId === resourceId &&
+              f.principalId === principalId &&
+              f.resourceKind === resourceKind
+            ),
+        ),
+        entry,
+      ],
+    }));
+    toast.success(`Shared "${resourceName}"`);
+  },
+
+  async revokeShare(client, resourceId, resourceKind, principalId, accountId) {
+    await applyShare(client, resourceKind, resourceId, principalId, null, accountId);
+
+    set((s) => ({
+      sharedByMe: s.sharedByMe.filter(
+        (f) =>
+          !(
+            f.resourceId === resourceId &&
+            f.principalId === principalId &&
+            f.resourceKind === resourceKind
+          ),
+      ),
+      sharedWithMe: s.sharedWithMe.filter(
+        (f) =>
+          !(
+            f.resourceId === resourceId &&
+            f.principalId === principalId &&
+            f.resourceKind === resourceKind
+          ),
+      ),
+    }));
+    toast.success("Access revoked");
+  },
+
+  async changeRole(
+    client,
+    resourceId,
+    resourceKind,
+    principalId,
+    role,
+    accountId,
+  ) {
+    const rights = resolveRights(resourceKind, role);
+    await applyShare(client, resourceKind, resourceId, principalId, rights, accountId);
+
+    set((s) => ({
+      sharedByMe: s.sharedByMe.map((f) =>
+        f.resourceId === resourceId &&
+        f.principalId === principalId &&
+        f.resourceKind === resourceKind
+          ? { ...f, role }
+          : f,
+      ),
+    }));
+    toast.success("Role updated");
+  },
+
+  async acceptShare(_client, share) {
+    set((s) => ({
+      sharedWithMe: s.sharedWithMe.map((f) =>
+        f.id === share.id ? { ...f, pending: false } : f,
+      ),
+    }));
+    toast.success(`Accepted share: ${share.resourceName}`);
+  },
+
+  async declineShare(_client, share) {
+    set((s) => ({
+      sharedWithMe: s.sharedWithMe.filter((f) => f.id !== share.id),
+    }));
+    toast.success(`Declined share: ${share.resourceName}`);
+  },
+}));
+
+async function applyShare(
+  client: IJMAPClient,
+  kind: SharedResourceKind,
+  resourceId: string,
+  principalId: string,
+  rights:
+    | MailboxRights
+    | CalendarRights
+    | AddressBookRights
+    | FileNodeRights
+    | null,
+  accountId?: string,
+): Promise<void> {
+  switch (kind) {
+    case "mailbox":
+      await client.setMailboxShare(
+        resourceId,
+        principalId,
+        rights as MailboxRights | null,
+        accountId,
+      );
+      break;
+    case "calendar":
+      await client.setCalendarShare(
+        resourceId,
+        principalId,
+        rights as CalendarRights | null,
+        accountId,
+      );
+      break;
+    case "addressBook":
+      await client.setAddressBookShare(
+        resourceId,
+        principalId,
+        rights as AddressBookRights | null,
+        accountId,
+      );
+      break;
+    case "file":
+      await client.setFileNodeShare(
+        resourceId,
+        principalId,
+        rights as FileNodeRights | null,
+        accountId,
+      );
+      break;
+  }
+}
+
+function detectMailboxPreset(r: MailboxRights): string {
+  for (const [name, preset] of Object.entries(MAILBOX_PRESETS)) {
+    const keys = Object.keys(preset) as (keyof MailboxRights)[];
+    if (
+      keys.every(
+        (k) =>
+          (preset[k] ?? false) === (r[k as keyof MailboxRights] ?? false),
+      )
+    ) {
+      return name;
+    }
+  }
+  return "custom";
+}
+
+function detectCalendarPreset(r: CalendarRights): string {
+  for (const [name, preset] of Object.entries(CALENDAR_PRESETS)) {
+    const keys = Object.keys(preset) as (keyof CalendarRights)[];
+    if (keys.every((k) => (preset[k] ?? false) === (r[k as keyof CalendarRights] ?? false))) {
+      return name;
+    }
+  }
+  return "custom";
+}
+
+function detectAddressBookPreset(r: AddressBookRights): string {
+  for (const [name, preset] of Object.entries(ADDRESS_BOOK_PRESETS)) {
+    const keys = Object.keys(preset) as (keyof AddressBookRights)[];
+    if (keys.every((k) => (preset[k] ?? false) === (r[k as keyof AddressBookRights] ?? false))) {
+      return name;
+    }
+  }
+  return "custom";
+}