feat: manage shared/group account settings from Accounts page

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

@@ -74,6 +74,7 @@ import { useEmailStore } from '@/stores/email-store';
 import { usePluginStore } from '@/stores/plugin-store';
 import { useThemeStore } from '@/stores/theme-store';
 import { useSettingsStore } from '@/stores/settings-store';
+import { useManagedAccountStore } from '@/stores/managed-account-store';
 import { useIsDesktop } from '@/hooks/use-media-query';
 import { NavigationRail } from '@/components/layout/navigation-rail';
 import { SidebarAppsModal } from '@/components/layout/sidebar-apps-modal';
@@ -385,6 +386,12 @@ export default function SettingsPage() {
   const sidebarAppsList = useSettingsStore((s) => s.sidebarApps);
   const proInterface = useSettingsStore((s) => s.proInterface);
 
+  // When set, the settings panel is scoped to a shared/group account: a reduced
+  // tab list and a "Managing: <name>" header. null = the user's own account.
+  const managedAccountId = useManagedAccountStore((s) => s.managedAccountId);
+  const managedAccount = useManagedAccountStore((s) => s.managedAccount);
+  const clearManagedAccount = useManagedAccountStore((s) => s.clear);
+
   // Build a per-tab haystack for fulltext search and a list of sub-results
   // (individual settings) per tab. Sub-results come from translation entries
   // that have a `label`/`title` field, plus dynamic content (installed
@@ -488,6 +495,10 @@ export default function SettingsPage() {
     return () => window.removeEventListener('settings-tab-change', handler);
   }, []);
 
+  // Leaving the settings panel drops any shared-account scope so it never
+  // leaks into the next visit or another session.
+  useEffect(() => () => clearManagedAccount(), [clearManagedAccount]);
+
   useEffect(() => {
     if (initialCheckDone && !isAuthenticated && !authLoading) {
       try { sessionStorage.setItem('redirect_after_login', window.location.pathname); } catch { /* ignore */ }
@@ -626,12 +637,28 @@ export default function SettingsPage() {
     ...(isFeatureEnabled('debugModeEnabled') ? [{ id: 'debug' as Tab, label: t('tabs.debug'), icon: tabIcons.debug, group: 'advanced' as TabGroup }] : []),
   ];
 
+  // In scoped (shared-account) mode, restrict to the account-relevant tabs the
+  // account actually advertises. Folders is intentionally excluded (mailbox CRUD
+  // is hardwired to the active account). Gated on both the per-account
+  // capability and the session-level support/feature flags.
+  const scopedTabIds: Tab[] = managedAccount
+    ? ([
+        managedAccount.capabilities.sieve && supportsSieve ? 'filters' : null,
+        managedAccount.capabilities.mail && supportsVacation ? 'vacation' : null,
+        managedAccount.capabilities.calendars && supportsCalendar ? 'calendar' : null,
+        managedAccount.capabilities.contacts && isFeatureEnabled('contactsEnabled') ? 'contacts' : null,
+      ].filter(Boolean) as Tab[])
+    : [];
+  const visibleTabs = managedAccountId
+    ? tabs.filter((tab) => scopedTabIds.includes(tab.id))
+    : tabs;
+
   // Group tabs by category
   const groupedTabs = tabGroupOrder
     .map((group) => ({
       group,
       label: t(`tab_groups.${group}`),
-      items: tabs.filter((tab) => tab.group === group),
+      items: visibleTabs.filter((tab) => tab.group === group),
     }))
     .filter((g) => g.items.length > 0);
 
@@ -659,9 +686,13 @@ export default function SettingsPage() {
         .filter((g) => g.items.length > 0)
     : groupedTabs;
 
-  // If active tab is not in the visible list (e.g., feature disabled), fall back.
+  // If active tab is not in the visible list (e.g., feature disabled, or scoped
-  const isActiveVisible = tabs.some((tab) => tab.id === activeTab);
+  // mode hides it), fall back. In scoped mode fall back to the first scoped tab;
-  const effectiveActiveTab: Tab = isActiveVisible ? activeTab : 'appearance';
+  // otherwise the usual 'appearance' default.
+  const isActiveVisible = visibleTabs.some((tab) => tab.id === activeTab);
+  const effectiveActiveTab: Tab = isActiveVisible
+    ? activeTab
+    : (managedAccountId ? (visibleTabs[0]?.id ?? 'appearance') : 'appearance');
 
   const handleTabSelect = (tabId: Tab) => {
     setActiveTab(tabId);
@@ -676,10 +707,26 @@ export default function SettingsPage() {
     setPendingHighlight({ tab: tabId, label: sub.label, pluginId: sub.pluginId });
   };
 
-  const activeTabLabel = tabs.find((tab) => tab.id === effectiveActiveTab)?.label ?? '';
+  const activeTabLabel = visibleTabs.find((tab) => tab.id === effectiveActiveTab)?.label ?? '';
 
   const renderTabContent = () => (
     <>
+      {managedAccountId && managedAccount && (
+        <button
+          type="button"
+          onClick={() => {
+            clearManagedAccount();
+            handleTabSelect('account');
+          }}
+          className="flex items-center gap-2 w-full mb-4 px-3 py-2 rounded-md border border-border bg-muted/40 hover:bg-muted text-left transition-colors"
+        >
+          <ArrowLeft className="w-4 h-4 text-muted-foreground flex-shrink-0" />
+          <span className="text-sm text-muted-foreground">{t('scoped.back')}</span>
+          <span className="ml-auto text-sm font-medium truncate">
+            {t('scoped.managing', { name: managedAccount.name })}
+          </span>
+        </button>
+      )}
       {effectiveActiveTab === 'account' && <AccountSettings />}
       {effectiveActiveTab === 'language' && <LanguageSettings />}
       {effectiveActiveTab === 'notifications' && <NotificationSettings />}
@@ -697,8 +744,16 @@ export default function SettingsPage() {
       {effectiveActiveTab === 'security' && <AccountSecuritySettings />}
       {effectiveActiveTab === 'encryption' && <SmimeSettings />}
       {effectiveActiveTab === 'content_senders' && <ContentSendersSettings />}
-      {effectiveActiveTab === 'calendar' && <><CalendarSettings /><div className="mt-8"><CalendarManagementSettings /></div></>}
+      {effectiveActiveTab === 'calendar' && (
-      {effectiveActiveTab === 'contacts' && <><ContactsSettings /><div className="mt-8"><AddressBookManagementSettings /></div></>}
+        managedAccountId
+          ? <CalendarManagementSettings />
+          : <><CalendarSettings /><div className="mt-8"><CalendarManagementSettings /></div></>
+      )}
+      {effectiveActiveTab === 'contacts' && (
+        managedAccountId
+          ? <AddressBookManagementSettings />
+          : <><ContactsSettings /><div className="mt-8"><AddressBookManagementSettings /></div></>
+      )}
       {effectiveActiveTab === 'files' && <FilesSettingsComponent />}
       {effectiveActiveTab === 'protocol_handlers' && <ProtocolHandlerSettings supportsCalendar={supportsCalendar} />}
       {effectiveActiveTab === 'sidebar_apps' && <SidebarAppsSettings />}

components/settings/account-settings.tsx

@@ -1,11 +1,13 @@
 "use client";
 
-import { useState, useRef, useCallback } from 'react';
+import { useState, useRef, useCallback, useMemo } from 'react';
 import { useTranslations } from 'next-intl';
-import { Check, GripVertical, Plus, Star, AlertCircle } from 'lucide-react';
+import { Check, GripVertical, Plus, Star, AlertCircle, ChevronRight } from 'lucide-react';
 import { useAuthStore } from '@/stores/auth-store';
 import { useEmailStore } from '@/stores/email-store';
 import { useAccountStore, type AccountEntry } from '@/stores/account-store';
+import { useManagedAccountStore } from '@/stores/managed-account-store';
+import type { SharedAccount } from '@/lib/jmap/types';
 import { SettingsSection, SettingItem } from './settings-section';
 import { Avatar } from '@/components/ui/avatar';
 import { Button } from '@/components/ui/button';
@@ -17,12 +19,30 @@ function hostnameOf(serverUrl: string): string {
   try { return new URL(serverUrl).hostname; } catch { return serverUrl; }
 }
 
+// First scoped settings tab to land on for a shared account, by capability.
+// Mirrors the scoped-tab gating in the settings page. null = nothing editable.
+function firstScopedTab(caps: SharedAccount['capabilities']): string | null {
+  if (caps.sieve) return 'filters';
+  if (caps.mail) return 'vacation';
+  if (caps.calendars) return 'calendar';
+  if (caps.contacts) return 'contacts';
+  return null;
+}
+
 export function AccountSettings() {
   const t = useTranslations('settings.account');
   const router = useRouter();
-  const { username, serverUrl, isDemoMode, primaryIdentity, authMode } = useAuthStore();
+  const { username, serverUrl, isDemoMode, primaryIdentity, authMode, client } = useAuthStore();
   const activeAccountId = useAuthStore((s) => s.activeAccountId);
   const switchAccount = useAuthStore((s) => s.switchAccount);
+  const setManagedAccount = useManagedAccountStore((s) => s.setManagedAccount);
+
+  // Shared/group accounts delegated to this session (excludes the user's own
+  // primary account). These can be drilled into for scoped settings editing.
+  const sharedAccounts = useMemo<SharedAccount[]>(
+    () => (client?.getSharedAccounts() ?? []).filter((a) => !a.isPrimary),
+    [client],
+  );
   const { quota } = useEmailStore();
   const accounts = useAccountStore((s) => s.accounts);
   const setDefaultAccount = useAccountStore((s) => s.setDefaultAccount);
@@ -82,6 +102,16 @@ export function AccountSettings() {
     router.push(`/login?mode=add-account` as never);
   }, [router]);
 
+  // Enter scoped settings mode for a shared/group account: set the managed
+  // account, then steer the settings panel to its first editable tab via the
+  // existing 'settings-tab-change' event the page already listens for.
+  const handleManageShared = useCallback((account: SharedAccount) => {
+    const tab = firstScopedTab(account.capabilities);
+    if (!tab) return;
+    setManagedAccount(account);
+    window.dispatchEvent(new CustomEvent('settings-tab-change', { detail: tab }));
+  }, [setManagedAccount]);
+
   return (
     <div className="space-y-8">
       <SettingsSection title={t('title')} description={t('description')}>
@@ -197,6 +227,44 @@ export function AccountSettings() {
           </div>
         </SettingsSection>
       )}
+
+      {/* Shared / group accounts delegated to this session. Clicking one drills
+          into a scoped settings view (filters, vacation, calendars, contacts). */}
+      {sharedAccounts.length > 0 && (
+        <SettingsSection title={t('shared_accounts.title')} description={t('shared_accounts.description')}>
+          <div className="space-y-2">
+            {sharedAccounts.map((acc) => {
+              const editable = firstScopedTab(acc.capabilities) !== null;
+              return (
+                <button
+                  key={acc.id}
+                  type="button"
+                  onClick={() => handleManageShared(acc)}
+                  disabled={!editable}
+                  className={cn(
+                    'flex items-center gap-3 w-full p-3 border border-border rounded-lg text-left transition-colors',
+                    editable ? 'hover:bg-muted/50 cursor-pointer' : 'opacity-60 cursor-not-allowed',
+                  )}
+                >
+                  <Avatar
+                    name={acc.name}
+                    size="sm"
+                    className="w-9 h-9 text-sm flex-shrink-0"
+                    disableFavicon
+                  />
+                  <div className="min-w-0 flex-1">
+                    <p className="text-sm font-medium truncate">{acc.name}</p>
+                    <p className="text-xs text-muted-foreground truncate">
+                      {t('shared_accounts.shared_label')}
+                    </p>
+                  </div>
+                  <ChevronRight className="w-4 h-4 text-muted-foreground flex-shrink-0" />
+                </button>
+              );
+            })}
+          </div>
+        </SettingsSection>
+      )}
     </div>
   );
 }

components/settings/address-book-management-settings.tsx

@@ -5,6 +5,7 @@ import { useTranslations } from "next-intl";
 import { Book, Pencil, Share2, Tag, Users } from "lucide-react";
 import { useContactStore } from "@/stores/contact-store";
 import { useAuthStore } from "@/stores/auth-store";
+import { useManagedAccountStore } from "@/stores/managed-account-store";
 import { toast } from "@/stores/toast-store";
 import { SettingsSection } from "./settings-section";
 import { cn } from "@/lib/utils";
@@ -71,6 +72,7 @@ export function AddressBookManagementSettings() {
   const tContacts = useTranslations("contacts");
   const tSettings = useTranslations("settings.contacts");
   const { client } = useAuthStore();
+  const managedAccountId = useManagedAccountStore((s) => s.managedAccountId);
   const { addressBooks, contacts, supportsSync, fetchAddressBooks, renameAddressBook, shareAddressBook, renameKeyword } = useContactStore();
   const [editingId, setEditingId] = useState<string | null>(null);
   const [editingKeyword, setEditingKeyword] = useState<string | null>(null);
@@ -205,9 +207,13 @@ export function AddressBookManagementSettings() {
     <>
     <SettingsSection title={tSettings("manage_title")} description={tSettings("manage_description")}>
       <div className="space-y-2">
-        {personal.map(renderBook)}
+        {/* In scoped mode (managing a shared account) hide the user's own
+            address books and show only the managed account's group. */}
+        {(managedAccountId ? [] : personal).map(renderBook)}
 
-        {Array.from(sharedGroups.entries()).map(([accountId, group]) => (
+        {Array.from(sharedGroups.entries())
+          .filter(([accountId]) => !managedAccountId || accountId === managedAccountId)
+          .map(([accountId, group]) => (
           <div key={accountId} className="mt-4 space-y-2">
             <h4 className="text-xs font-medium text-muted-foreground uppercase tracking-wider flex items-center gap-1.5">
               <Share2 className="w-3 h-3" />
@@ -223,6 +229,9 @@ export function AddressBookManagementSettings() {
       </div>
     </SettingsSection>
 
+    {/* Contact categories come from the active account's contacts, not the
+        shared account, so hide them while scoped to a shared account. */}
+    {!managedAccountId && (
     <div className="mt-8">
       <SettingsSection title={tSettings("categories_title")} description={tSettings("categories_description")}>
         <div className="space-y-2">
@@ -267,6 +276,7 @@ export function AddressBookManagementSettings() {
         </div>
       </SettingsSection>
     </div>
+    )}
 
     {sharingId && client && (() => {
       const book = addressBooks.find((b) => b.id === sharingId);

components/settings/calendar-management-settings.tsx

@@ -14,6 +14,7 @@ import { cn, formatDateTime, redactUrlCredentials } from '@/lib/utils';
 import { ICalImportModal } from '@/components/calendar/ical-import-modal';
 import { ICalSubscriptionModal } from '@/components/calendar/ical-subscription-modal';
 import { useSettingsStore } from '@/stores/settings-store';
+import { useManagedAccountStore } from '@/stores/managed-account-store';
 import { apiFetch } from '@/lib/browser-navigation';
 import { CALENDAR_COLORS, sharedCalendarColorKey } from '@/lib/shared-calendar-colors';
 
@@ -137,6 +138,7 @@ export { CalendarColorPicker, CALENDAR_COLORS };
 export function CalendarManagementSettings() {
   const t = useTranslations('calendar.management');
   const { client, serverUrl, username } = useAuthStore();
+  const managedAccountId = useManagedAccountStore((s) => s.managedAccountId);
   const { calendars, updateCalendar, shareCalendar, createCalendar, removeCalendar, clearCalendarEvents, fetchCalendars, icalSubscriptions: allSubs, removeICalSubscription, refreshICalSubscription, isSubscriptionCalendar } = useCalendarStore();
   // Subscriptions are persisted globally but scoped per JMAP account via
   // accountId. Legacy entries with no accountId show in the active account.
@@ -388,7 +390,10 @@ export function CalendarManagementSettings() {
   return (
     <SettingsSection title={t('title')} description={t('description')}>
       <div className="space-y-2">
-        {calendars.filter(cal => !isSubscriptionCalendar(cal.id)).map((cal) => {
+        {calendars
+          .filter(cal => !isSubscriptionCalendar(cal.id))
+          .filter(cal => !managedAccountId || cal.accountId === managedAccountId)
+          .map((cal) => {
           const color = (cal.isShared && sharedCalendarColors[sharedCalendarColorKey(cal)]) || cal.color || '#3b82f6';
 
           if (editingId === cal.id) {

components/settings/filter-settings.tsx

@@ -12,7 +12,9 @@ import { useEmailStore } from "@/stores/email-store";
 import { useSettingsStore } from "@/stores/settings-store";
 import { toast } from "@/stores/toast-store";
 import type { FilterRule } from "@/lib/jmap/sieve-types";
+import type { Mailbox } from "@/lib/jmap/types";
 import { useVacationStore } from "@/stores/vacation-store";
+import { useManagedAccountStore } from "@/stores/managed-account-store";
 import {
   Plus,
   GripVertical,
@@ -157,7 +159,7 @@ export function FilterSettings() {
   const t = useTranslations("settings.filters");
   const tNotifications = useTranslations("notifications");
   const { client } = useAuthStore();
-  const mailboxes = useEmailStore((s) => s.mailboxes);
+  const storeMailboxes = useEmailStore((s) => s.mailboxes);
   const expandedFilterView = useSettingsStore((s) => s.expandedFilterView);
   const updateSetting = useSettingsStore((s) => s.updateSetting);
 
@@ -170,7 +172,7 @@ export function FilterSettings() {
     isOpaque,
     rawScript,
     vacationSettings,
-    fetchFilters,
+    selectAccount,
     saveFilters,
     addRule,
     updateRule,
@@ -182,7 +184,41 @@ export function FilterSettings() {
     validateScript,
   } = useFilterStore();
 
-  const vacationEnabled = useVacationStore((s) => s.isEnabled) || vacationSettings?.isEnabled;
+  // Scoped to a shared/group account when the settings panel is managing one.
+  const managedAccountId = useManagedAccountStore((s) => s.managedAccountId);
+  const isPrimaryAccount = !managedAccountId;
+
+  // Folders offered as "move to" targets in the rule editor must belong to the
+  // account whose filters we're editing. For a shared account, fetch that
+  // account's mailboxes (the email store only holds the active account's). They
+  // are this account's own folders within its Sieve context, so present them as
+  // non-shared — otherwise the rule modal filters them out (it drops isShared
+  // mailboxes, which are normally other accounts' folders merged into the view).
+  const [scopedMailboxes, setScopedMailboxes] = useState<Mailbox[]>([]);
+  useEffect(() => {
+    if (!client || !managedAccountId) {
+      setScopedMailboxes([]);
+      return;
+    }
+    let cancelled = false;
+    void client
+      .getMailboxes(managedAccountId)
+      .then((mbs) => {
+        if (!cancelled) setScopedMailboxes(mbs.map((mb) => ({ ...mb, isShared: false })));
+      })
+      .catch(() => {
+        if (!cancelled) setScopedMailboxes([]);
+      });
+    return () => { cancelled = true; };
+  }, [client, managedAccountId]);
+
+  const mailboxes = managedAccountId ? scopedMailboxes : storeMailboxes;
+
+  const vacationStoreEnabled = useVacationStore((s) => s.isEnabled);
+  // Vacation uses a separate per-(primary)-account mechanism (RFC 9661), so the
+  // "vacation active" banner only applies when editing the personal account.
+  const vacationEnabled =
+    isPrimaryAccount && (vacationStoreEnabled || vacationSettings?.isEnabled);
 
   const [editingRule, setEditingRule] = useState<FilterRule | undefined>();
   const [showRuleModal, setShowRuleModal] = useState(false);
@@ -194,9 +230,12 @@ export function FilterSettings() {
 
   useEffect(() => {
     if (client && isSupported) {
-      void fetchFilters(client);
+      // Always pass a concrete account id (managed shared account, or the
+      // primary Sieve account) so switching never falls back to a stale
+      // previously-selected account.
+      void selectAccount(client, managedAccountId ?? client.getSieveAccountId());
     }
-  }, [client, isSupported, fetchFilters]);
+  }, [client, isSupported, managedAccountId, selectAccount]);
 
   const handleToggle = useCallback(
     async (ruleId: string) => {

components/settings/vacation-settings.tsx

@@ -6,6 +6,7 @@ import { SettingsSection, SettingItem, ToggleSwitch } from './settings-section';
 import { Button } from '@/components/ui/button';
 import { useVacationStore } from '@/stores/vacation-store';
 import { useAuthStore } from '@/stores/auth-store';
+import { useManagedAccountStore } from '@/stores/managed-account-store';
 import { Loader2, AlertTriangle, Eye, EyeOff } from 'lucide-react';
 import { toast } from '@/stores/toast-store';
 
@@ -19,6 +20,7 @@ export function VacationSettings() {
   const t = useTranslations('settings.vacation');
   const tNotifications = useTranslations('notifications');
   const { client } = useAuthStore();
+  const managedAccountId = useManagedAccountStore((s) => s.managedAccountId);
   const {
     isEnabled,
     fromDate,
@@ -43,9 +45,9 @@ export function VacationSettings() {
 
   useEffect(() => {
     if (client && isSupported) {
-      void fetchVacationResponse(client);
+      void fetchVacationResponse(client, managedAccountId ?? undefined);
     }
-  }, [client, isSupported, fetchVacationResponse]);
+  }, [client, isSupported, managedAccountId, fetchVacationResponse]);
 
   useEffect(() => {
     setLocalEnabled(isEnabled);
@@ -101,7 +103,7 @@ export function VacationSettings() {
         toDate: localToDate || null,
         subject: localSubject,
         textBody: localTextBody,
-      });
+      }, managedAccountId ?? undefined);
 
       toast.success(tNotifications('vacation_saved'));
     } catch (error) {

lib/demo/demo-client.ts

@@ -1,5 +1,5 @@
 import type { IJMAPClient } from '@/lib/jmap/client-interface';
-import type { Email, Mailbox, StateChange, AccountStates, Thread, Identity, EmailAddress, ContactCard, AddressBook, VacationResponse, Calendar, CalendarEvent, CalendarEventFilter, CalendarTask, FileNode, ScheduledEmail, SendEmailResult } from '@/lib/jmap/types';
+import type { Email, Mailbox, StateChange, AccountStates, Thread, Identity, EmailAddress, ContactCard, AddressBook, VacationResponse, Calendar, CalendarEvent, CalendarEventFilter, CalendarTask, FileNode, ScheduledEmail, SendEmailResult, SharedAccount } from '@/lib/jmap/types';
 import type { SieveScript, SieveCapabilities } from '@/lib/jmap/sieve-types';
 import { getDemoData, type DemoData } from './demo-data';
 import { generateDemoId } from './demo-utils';
@@ -118,7 +118,7 @@ export class DemoJMAPClient implements IJMAPClient {
 
   // ── Mailboxes ─────────────────────────────────────────────────
 
-  async getMailboxes(): Promise<Mailbox[]> { return [...this.data.mailboxes]; }
+  async getMailboxes(_accountId?: string): Promise<Mailbox[]> { return [...this.data.mailboxes]; }
   async getAllMailboxes(): Promise<Mailbox[]> { return [...this.data.mailboxes]; }
 
   async createMailbox(name: string, parentId?: string): Promise<Mailbox> {
@@ -603,9 +603,9 @@ export class DemoJMAPClient implements IJMAPClient {
 
   // ── Vacation ──────────────────────────────────────────────────
 
-  async getVacationResponse(): Promise<VacationResponse> { return { ...this.data.vacationResponse }; }
+  async getVacationResponse(_accountId?: string): Promise<VacationResponse> { return { ...this.data.vacationResponse }; }
 
-  async setVacationResponse(updates: Partial<VacationResponse>): Promise<void> {
+  async setVacationResponse(updates: Partial<VacationResponse>, _accountId?: string): Promise<void> {
     Object.assign(this.data.vacationResponse, updates);
   }
 
@@ -849,19 +849,34 @@ export class DemoJMAPClient implements IJMAPClient {
 
   // ── Sieve / Filters ──────────────────────────────────────────
 
+  getSharedAccounts(): SharedAccount[] {
+    return [{
+      id: 'demo-account',
+      name: 'Demo',
+      isPrimary: true,
+      capabilities: { mail: true, sieve: true, calendars: true, contacts: true, filenode: true },
+    }];
+  }
+
   getSieveAccountId(): string { return 'demo-account'; }
 
-  getSieveCapabilities(): SieveCapabilities | null {
+  getSieveAccounts(): { id: string; name: string; isPrimary: boolean }[] {
+    return this.getSharedAccounts()
+      .filter((a) => a.isPrimary || a.capabilities.sieve)
+      .map(({ id, name, isPrimary }) => ({ id, name, isPrimary }));
+  }
+
+  getSieveCapabilities(_accountId?: string): SieveCapabilities | null {
     return { ...this.data.sieveCapabilities };
   }
 
-  async getSieveScripts(): Promise<SieveScript[]> { return [...this.data.sieveScripts]; }
+  async getSieveScripts(_accountId?: string): Promise<SieveScript[]> { return [...this.data.sieveScripts]; }
 
-  async getSieveScriptContent(blobId: string): Promise<string> {
+  async getSieveScriptContent(blobId: string, _accountId?: string): Promise<string> {
     return this.data.sieveContent[blobId] ?? '';
   }
 
-  async createSieveScript(name: string, content: string, activate?: boolean): Promise<SieveScript> {
+  async createSieveScript(name: string, content: string, activate?: boolean, _accountId?: string): Promise<SieveScript> {
     const blobId = generateDemoId('sieve-blob');
     const script: SieveScript = { id: generateDemoId('sieve'), name, blobId, isActive: activate ?? false };
     this.data.sieveScripts.push(script);
@@ -874,7 +889,7 @@ export class DemoJMAPClient implements IJMAPClient {
     return script;
   }
 
-  async updateSieveScript(scriptId: string, content: string, activate?: boolean): Promise<void> {
+  async updateSieveScript(scriptId: string, content: string, activate?: boolean, _accountId?: string): Promise<void> {
     const script = this.data.sieveScripts.find(s => s.id === scriptId);
     if (!script) return;
     const blobId = generateDemoId('sieve-blob');
@@ -890,11 +905,11 @@ export class DemoJMAPClient implements IJMAPClient {
     }
   }
 
-  async deleteSieveScript(scriptId: string): Promise<void> {
+  async deleteSieveScript(scriptId: string, _accountId?: string): Promise<void> {
     this.data.sieveScripts = this.data.sieveScripts.filter(s => s.id !== scriptId);
   }
 
-  async validateSieveScript(): Promise<{ isValid: boolean; errors?: string[] }> {
+  async validateSieveScript(_content?: string, _accountId?: string): Promise<{ isValid: boolean; errors?: string[] }> {
     return { isValid: true };
   }
 

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 } from "./types";
+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 { SieveScript, SieveCapabilities } from "./sieve-types";
 
 /**
@@ -71,7 +71,7 @@ export interface IJMAPClient {
   getQuota(): Promise<{ used: number; total: number } | null>;
 
   // ── Mailboxes ─────────────────────────────────────────────────
-  getMailboxes(): Promise<Mailbox[]>;
+  getMailboxes(accountId?: string): Promise<Mailbox[]>;
   getAllMailboxes(): Promise<Mailbox[]>;
   createMailbox(name: string, parentId?: string): Promise<Mailbox>;
   updateMailbox(mailboxId: string, changes: { name?: string; parentId?: string | null; role?: string | null; sortOrder?: number }): Promise<void>;
@@ -239,8 +239,8 @@ export interface IJMAPClient {
   deleteIdentity(identityId: string): Promise<void>;
 
   // ── Vacation ──────────────────────────────────────────────────
-  getVacationResponse(): Promise<VacationResponse>;
+  getVacationResponse(accountId?: string): Promise<VacationResponse>;
-  setVacationResponse(updates: Partial<VacationResponse>): Promise<void>;
+  setVacationResponse(updates: Partial<VacationResponse>, accountId?: string): Promise<void>;
 
   // ── Contacts ──────────────────────────────────────────────────
   getContactsAccountId(): string;
@@ -294,15 +294,19 @@ export interface IJMAPClient {
   setAddressBookShare(addressBookId: string, principalId: string, rights: AddressBookRights | null, targetAccountId?: string): Promise<void>;
   setFileNodeShare(fileNodeId: string, principalId: string, rights: FileNodeRights | null, targetAccountId?: string): Promise<void>;
 
+  // ── Accounts (primary + shared/group) ────────────────────────
+  getSharedAccounts(): SharedAccount[];
+
   // ── Sieve / Filters ──────────────────────────────────────────
   getSieveAccountId(): string;
-  getSieveCapabilities(): SieveCapabilities | null;
+  getSieveAccounts(): { id: string; name: string; isPrimary: boolean }[];
-  getSieveScripts(): Promise<SieveScript[]>;
+  getSieveCapabilities(accountId?: string): SieveCapabilities | null;
-  getSieveScriptContent(blobId: string): Promise<string>;
+  getSieveScripts(accountId?: string): Promise<SieveScript[]>;
-  createSieveScript(name: string, content: string, activate?: boolean): Promise<SieveScript>;
+  getSieveScriptContent(blobId: string, accountId?: string): Promise<string>;
-  updateSieveScript(scriptId: string, content: string, activate?: boolean): Promise<void>;
+  createSieveScript(name: string, content: string, activate?: boolean, accountId?: string): Promise<SieveScript>;
-  deleteSieveScript(scriptId: string): Promise<void>;
+  updateSieveScript(scriptId: string, content: string, activate?: boolean, accountId?: string): Promise<void>;
-  validateSieveScript(content: string): Promise<{ isValid: boolean; errors?: string[] }>;
+  deleteSieveScript(scriptId: string, accountId?: string): Promise<void>;
+  validateSieveScript(content: string, accountId?: string): Promise<{ isValid: boolean; errors?: string[] }>;
 
   // ── Files (WebDAV / FileNode) ─────────────────────────────────
   getFilesAccountId(): string;

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 } from "./types";
+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 { SieveScript, SieveCapabilities } from "./sieve-types";
 import type { IJMAPClient } from "./client-interface";
 import { toWildcardQuery } from "./search-utils";
@@ -897,16 +897,17 @@ export class JMAPClient implements IJMAPClient {
     }
   }
 
-  async getMailboxes(): Promise<Mailbox[]> {
+  async getMailboxes(accountId?: string): Promise<Mailbox[]> {
+    const acctId = accountId || this.accountId;
     try {
       const response = await this.request([
-        ["Mailbox/get", { accountId: this.accountId }, "0"]
+        ["Mailbox/get", { accountId: acctId }, "0"]
       ]);
 
       if (response.methodResponses?.[0]?.[0] === "Mailbox/get") {
         const rawMailboxes = (response.methodResponses[0][1].list || []) as JMAPMailbox[];
 
-        debug.log('jmap', `[JMAP Mailbox] getMailboxes returned ${rawMailboxes.length} mailboxes for account ${this.accountId}`);
+        debug.log('jmap', `[JMAP Mailbox] getMailboxes returned ${rawMailboxes.length} mailboxes for account ${acctId}`);
 
         // Warn if response might be truncated
         const maxObjects = this.getMaxObjectsInGet();
@@ -940,9 +941,9 @@ export class JMAPClient implements IJMAPClient {
           unreadThreads: mb.unreadThreads ?? 0,
           myRights: mb.myRights || DEFAULT_MAILBOX_RIGHTS,
           isSubscribed: mb.isSubscribed ?? true,
-          accountId: this.accountId,
+          accountId: acctId,
-          accountName: this.accounts[this.accountId]?.name || this.username,
+          accountName: this.accounts[acctId]?.name || this.username,
-          isShared: false,
+          isShared: acctId !== this.accountId,
         }) as Mailbox);
       }
 
@@ -2082,10 +2083,10 @@ export class JMAPClient implements IJMAPClient {
     return ["urn:ietf:params:jmap:core", "urn:ietf:params:jmap:mail", "urn:ietf:params:jmap:vacationresponse"];
   }
 
-  async getVacationResponse(): Promise<VacationResponse> {
+  async getVacationResponse(accountId?: string): Promise<VacationResponse> {
     const response = await this.request([
       ["VacationResponse/get", {
-        accountId: this.accountId,
+        accountId: accountId || this.accountId,
         ids: ["singleton"],
       }, "0"]
     ], this.vacationUsing());
@@ -2109,10 +2110,10 @@ export class JMAPClient implements IJMAPClient {
     throw new Error("Failed to fetch vacation response: unexpected server response");
   }
 
-  async setVacationResponse(updates: Partial<VacationResponse>): Promise<void> {
+  async setVacationResponse(updates: Partial<VacationResponse>, accountId?: string): Promise<void> {
     const response = await this.request([
       ["VacationResponse/set", {
-        accountId: this.accountId,
+        accountId: accountId || this.accountId,
         update: {
           "singleton": updates,
         },
@@ -3421,18 +3422,79 @@ export class JMAPClient implements IJMAPClient {
     return ["urn:ietf:params:jmap:core", "urn:ietf:params:jmap:sieve"];
   }
 
-  getSieveCapabilities(): SieveCapabilities | null {
+  /**
-    const sieveAccountId = this.getSieveAccountId();
+   * Accounts (primary + shared/group) visible in this session, each tagged with
+   * the capabilities it advertises. Unifies the per-feature enumeration that
+   * getCalendarCapableAccountIds()/getContactCapableAccountIds()/
+   * getFilesCapableAccountIds() do: a non-primary account is included when it
+   * advertises a capability OR is a non-personal (shared/group) account, since
+   * Stalwart doesn't always advertise capabilities on those even when they
+   * support the feature. Primary account first; name from the session account
+   * (primary falls back to the username). Drives the settings "Shared with me"
+   * list and the scoped-settings tab gating.
+   */
+  getSharedAccounts(): SharedAccount[] {
+    const primaryId = this.getSieveAccountId();
+    const toEntry = (id: string, isPrimary: boolean): SharedAccount => {
+      const account = this.accounts[id];
+      const caps = account?.accountCapabilities;
+      const shared = !account?.isPersonal;
+      return {
+        id,
+        name: account?.name || (isPrimary ? (this.username || id) : id),
+        isPrimary,
+        capabilities: {
+          mail: !!caps?.["urn:ietf:params:jmap:mail"] || shared,
+          sieve: !!caps?.["urn:ietf:params:jmap:sieve"] || shared,
+          calendars: !!caps?.["urn:ietf:params:jmap:calendars"] || shared,
+          contacts: !!caps?.["urn:ietf:params:jmap:contacts"] || shared,
+          filenode: !!caps?.["urn:ietf:params:jmap:filenode"] || shared,
+        },
+      };
+    };
+
+    const result = [toEntry(primaryId, true)];
+    for (const id of Object.keys(this.accounts)) {
+      if (id === primaryId) continue;
+      const account = this.accounts[id];
+      // Mirror the per-feature helpers: include any non-personal account, plus
+      // accounts that advertise at least one editable capability.
+      const caps = account.accountCapabilities;
+      const advertisesAny =
+        !!caps?.["urn:ietf:params:jmap:mail"] ||
+        !!caps?.["urn:ietf:params:jmap:sieve"] ||
+        !!caps?.["urn:ietf:params:jmap:calendars"] ||
+        !!caps?.["urn:ietf:params:jmap:contacts"] ||
+        !!caps?.["urn:ietf:params:jmap:filenode"];
+      if (!account.isPersonal || advertisesAny) {
+        result.push(toEntry(id, false));
+      }
+    }
+    return result;
+  }
+
+  /**
+   * Sieve-capable accounts (primary + shared/group), for the filters UI.
+   * Thin wrapper over getSharedAccounts() filtered to the sieve capability.
+   */
+  getSieveAccounts(): { id: string; name: string; isPrimary: boolean }[] {
+    return this.getSharedAccounts()
+      .filter((a) => a.isPrimary || a.capabilities.sieve)
+      .map(({ id, name, isPrimary }) => ({ id, name, isPrimary }));
+  }
+
+  getSieveCapabilities(accountId?: string): SieveCapabilities | null {
+    const sieveAccountId = accountId || this.getSieveAccountId();
     const accountInfo = this.accounts[sieveAccountId];
     if (!accountInfo?.accountCapabilities) return null;
     const caps = accountInfo.accountCapabilities["urn:ietf:params:jmap:sieve"];
     return (caps as SieveCapabilities) || null;
   }
 
-  async getSieveScripts(): Promise<SieveScript[]> {
+  async getSieveScripts(accountId?: string): Promise<SieveScript[]> {
     const response = await this.request([
       ["SieveScript/get", {
-        accountId: this.getSieveAccountId(),
+        accountId: accountId || this.getSieveAccountId(),
       }, "0"]
     ], this.sieveUsing());
 
@@ -3442,21 +3504,26 @@ export class JMAPClient implements IJMAPClient {
     throw new Error('Failed to fetch Sieve scripts');
   }
 
-  async getSieveScriptContent(blobId: string): Promise<string> {
+  async getSieveScriptContent(blobId: string, accountId?: string): Promise<string> {
-    const url = this.getBlobDownloadUrl(blobId, 'script.sieve', 'application/sieve');
+    // Blobs are scoped per account, so a shared/group account's script must be
+    // downloaded against that owner's accountId, not the primary one.
+    const url = this.getBlobDownloadUrl(
+      blobId, 'script.sieve', 'application/sieve', accountId || this.getSieveAccountId(),
+    );
     const response = await this.authenticatedFetch(url, {});
     if (!response.ok) throw new Error(`Failed to download script: ${response.status}`);
     return response.text();
   }
 
-  private async uploadSieveBlob(content: string): Promise<string> {
+  private async uploadSieveBlob(content: string, accountId?: string): Promise<string> {
     if (!this.session?.uploadUrl) {
       throw new Error('Upload URL not available');
     }
 
+    const targetAccountId = accountId || this.getSieveAccountId();
     const uploadUrl = this.session.uploadUrl.replace(
       '{accountId}',
-      encodeURIComponent(this.getSieveAccountId())
+      encodeURIComponent(targetAccountId)
     );
 
     const response = await this.authenticatedFetch(uploadUrl, {
@@ -3474,17 +3541,17 @@ export class JMAPClient implements IJMAPClient {
 
     const result = await response.json();
     if (result.blobId) return result.blobId;
-    const blobInfo = result[this.getSieveAccountId()];
+    const blobInfo = result[targetAccountId];
     if (blobInfo?.blobId) return blobInfo.blobId;
     throw new Error('Invalid upload response: blobId not found');
   }
 
-  async createSieveScript(name: string, content: string, activate?: boolean): Promise<SieveScript> {
+  async createSieveScript(name: string, content: string, activate?: boolean, accountId?: string): Promise<SieveScript> {
-    const blobId = await this.uploadSieveBlob(content);
+    const targetAccountId = accountId || this.getSieveAccountId();
-    const accountId = this.getSieveAccountId();
+    const blobId = await this.uploadSieveBlob(content, targetAccountId);
 
     const setArgs: Record<string, unknown> = {
-      accountId,
+      accountId: targetAccountId,
       create: {
         "new-script": { name, blobId }
       },
@@ -3505,7 +3572,7 @@ export class JMAPClient implements IJMAPClient {
       }
       const createdId = result.created?.["new-script"]?.id;
       if (createdId) {
-        const scripts = await this.getSieveScripts();
+        const scripts = await this.getSieveScripts(targetAccountId);
         const script = scripts.find(s => s.id === createdId);
         if (script) return script;
       }
@@ -3513,12 +3580,12 @@ export class JMAPClient implements IJMAPClient {
     throw new Error("Failed to create sieve script");
   }
 
-  async updateSieveScript(scriptId: string, content: string, activate?: boolean): Promise<void> {
+  async updateSieveScript(scriptId: string, content: string, activate?: boolean, accountId?: string): Promise<void> {
-    const blobId = await this.uploadSieveBlob(content);
+    const targetAccountId = accountId || this.getSieveAccountId();
-    const accountId = this.getSieveAccountId();
+    const blobId = await this.uploadSieveBlob(content, targetAccountId);
 
     const setArgs: Record<string, unknown> = {
-      accountId,
+      accountId: targetAccountId,
       update: {
         [scriptId]: { blobId }
       },
@@ -3542,12 +3609,10 @@ export class JMAPClient implements IJMAPClient {
     throw new Error("Failed to update sieve script");
   }
 
-  async deleteSieveScript(scriptId: string): Promise<void> {
+  async deleteSieveScript(scriptId: string, accountId?: string): Promise<void> {
-    const accountId = this.getSieveAccountId();
-
     const response = await this.request([
       ["SieveScript/set", {
-        accountId,
+        accountId: accountId || this.getSieveAccountId(),
         destroy: [scriptId]
       }, "0"]
     ], this.sieveUsing());
@@ -3563,12 +3628,10 @@ export class JMAPClient implements IJMAPClient {
     throw new Error("Failed to delete sieve script");
   }
 
-  async activateSieveScript(scriptId: string): Promise<void> {
+  async activateSieveScript(scriptId: string, accountId?: string): Promise<void> {
-    const accountId = this.getSieveAccountId();
-
     const response = await this.request([
       ["SieveScript/set", {
-        accountId,
+        accountId: accountId || this.getSieveAccountId(),
         onSuccessActivateScript: scriptId,
       }, "0"]
     ], this.sieveUsing());
@@ -3582,12 +3645,10 @@ export class JMAPClient implements IJMAPClient {
     }
   }
 
-  async deactivateSieveScript(): Promise<void> {
+  async deactivateSieveScript(accountId?: string): Promise<void> {
-    const accountId = this.getSieveAccountId();
-
     const response = await this.request([
       ["SieveScript/set", {
-        accountId,
+        accountId: accountId || this.getSieveAccountId(),
         onSuccessActivateScript: null,
       }, "0"]
     ], this.sieveUsing());
@@ -3601,13 +3662,13 @@ export class JMAPClient implements IJMAPClient {
     }
   }
 
-  async validateSieveScript(content: string): Promise<{ isValid: boolean; errors?: string[] }> {
+  async validateSieveScript(content: string, accountId?: string): Promise<{ isValid: boolean; errors?: string[] }> {
-    const blobId = await this.uploadSieveBlob(content);
+    const targetAccountId = accountId || this.getSieveAccountId();
-    const accountId = this.getSieveAccountId();
+    const blobId = await this.uploadSieveBlob(content, targetAccountId);
 
     const response = await this.request([
       ["SieveScript/validate", {
-        accountId,
+        accountId: targetAccountId,
         blobId,
       }, "0"]
     ], this.sieveUsing());

lib/jmap/types.ts

@@ -3,6 +3,25 @@ export interface EmailHeader {
   value: string;
 }
 
+/**
+ * A session-visible account (the user's own primary account plus any
+ * shared/group accounts delegated to them), tagged with the capabilities it
+ * advertises. Produced by client.getSharedAccounts(); drives the settings
+ * "Shared with me" list and the scoped-settings tab gating.
+ */
+export interface SharedAccount {
+  id: string;
+  name: string;
+  isPrimary: boolean;
+  capabilities: {
+    mail: boolean;
+    sieve: boolean;
+    calendars: boolean;
+    contacts: boolean;
+    filenode: boolean;
+  };
+}
+
 export interface Email {
   id: string;
   threadId: string;

locales/en/common.json

@@ -1289,8 +1289,17 @@
         "move_down": "Move down",
         "drag_handle": "Drag to reorder",
         "add": "Add account"
+      },
+      "shared_accounts": {
+        "title": "Shared with me",
+        "description": "Group and shared accounts you can manage. Select one to edit its filters, vacation responder, calendars, and contacts.",
+        "shared_label": "Shared account"
       }
     },
+    "scoped": {
+      "back": "Back to my account",
+      "managing": "Managing: {name}"
+    },
     "security": {
       "title": "Account Security",
       "description": "Manage your password, two-factor authentication, and security settings",

stores/__tests__/filter-store.test.ts

@@ -3,6 +3,13 @@ import { useFilterStore } from '../filter-store';
 import type { FilterRule } from '@/lib/jmap/sieve-types';
 import type { IJMAPClient } from '@/lib/jmap/client-interface';
 
+// Minimal account plumbing every fetchFilters mock needs now that the store
+// resolves a target Sieve account before fetching scripts.
+const sieveAccountMock = {
+  getSieveAccountId: () => 'primary',
+  getSieveAccounts: () => [{ id: 'primary', name: 'Me', isPrimary: true }],
+};
+
 const makeRule = (overrides: Partial<FilterRule> = {}): FilterRule => ({
   id: 'rule-1',
   name: 'Test Rule',
@@ -153,6 +160,7 @@ describe('filter-store', () => {
   describe('fetchFilters', () => {
     it('parses external rules from scripts without metadata', async () => {
       const mockClient = {
+        ...sieveAccountMock,
         getSieveCapabilities: () => null,
         getSieveScripts: async () => [{ id: 's1', name: 'main', blobId: 'b1', isActive: true }],
         getSieveScriptContent: async () => 'require ["fileinto"];\nif header :contains "From" "x" { fileinto "Y"; }',
@@ -165,6 +173,7 @@ describe('filter-store', () => {
 
     it('sets isOpaque for truly unparseable content', async () => {
       const mockClient = {
+        ...sieveAccountMock,
         getSieveCapabilities: () => null,
         getSieveScripts: async () => [{ id: 's1', name: 'main', blobId: 'b1', isActive: true }],
         getSieveScriptContent: async () => '/* @metadata:begin\n{corrupt\n@metadata:end */',
@@ -178,6 +187,7 @@ describe('filter-store', () => {
       const { generateScript } = await import('@/lib/sieve/generator');
       const script = generateScript(rules);
       const mockClient = {
+        ...sieveAccountMock,
         getSieveCapabilities: () => null,
         getSieveScripts: async () => [{ id: 's1', name: 'main', blobId: 'b1', isActive: true }],
         getSieveScriptContent: async () => script,
@@ -189,6 +199,7 @@ describe('filter-store', () => {
 
     it('should handle empty script list', async () => {
       const mockClient = {
+        ...sieveAccountMock,
         getSieveCapabilities: () => null,
         getSieveScripts: async () => [],
         getSieveScriptContent: async () => '',
@@ -200,6 +211,7 @@ describe('filter-store', () => {
 
     it('should set error on failure', async () => {
       const mockClient = {
+        ...sieveAccountMock,
         getSieveCapabilities: () => null,
         getSieveScripts: async () => { throw new Error('Network error'); },
       };
@@ -313,6 +325,7 @@ describe('filter-store', () => {
       const inactiveRules = [makeRule({ name: 'Inactive' })];
 
       const mockClient = {
+        ...sieveAccountMock,
         getSieveCapabilities: () => null,
         getSieveScripts: async () => [
           { id: 's1', name: 'old', blobId: 'b1', isActive: false },
@@ -331,6 +344,7 @@ describe('filter-store', () => {
     it('should set sieveCapabilities from client', async () => {
       const caps = { implementation: 'test', maxSizeScript: 10000, sieveExtensions: ['fileinto'], notificationMethods: [], externalLists: [] };
       const mockClient = {
+        ...sieveAccountMock,
         getSieveCapabilities: () => caps,
         getSieveScripts: async () => [],
       };
@@ -343,6 +357,7 @@ describe('filter-store', () => {
       const rules = [makeRule()];
       const script = generateScript(rules);
       const mockClient = {
+        ...sieveAccountMock,
         getSieveCapabilities: () => null,
         getSieveScripts: async () => [{ id: 's1', name: 'main', blobId: 'b1', isActive: true }],
         getSieveScriptContent: async () => script,
@@ -357,6 +372,7 @@ describe('filter-store', () => {
       const script = generateScript(rules);
 
       const mockClient = {
+        ...sieveAccountMock,
         getSieveCapabilities: () => null,
         getSieveScripts: async () => [
           { id: 'vac-1', name: 'vacation', blobId: 'bv', isActive: true },
@@ -375,6 +391,7 @@ describe('filter-store', () => {
 
     it('should handle only vacation script present (no filter scripts)', async () => {
       const mockClient = {
+        ...sieveAccountMock,
         getSieveCapabilities: () => null,
         getSieveScripts: async () => [
           { id: 'vac-1', name: 'vacation', blobId: 'bv', isActive: true },
@@ -384,5 +401,72 @@ describe('filter-store', () => {
       expect(useFilterStore.getState().activeScriptId).toBeNull();
       expect(useFilterStore.getState().rules).toEqual([]);
     });
+
+    it('populates availableAccounts and defaults to the primary account', async () => {
+      const mockClient = {
+        getSieveAccountId: () => 'primary',
+        getSieveAccounts: () => [
+          { id: 'primary', name: 'Me', isPrimary: true },
+          { id: 'group', name: 'Sales', isPrimary: false },
+        ],
+        getSieveCapabilities: () => null,
+        getSieveScripts: async () => [],
+      };
+      await useFilterStore.getState().fetchFilters(mockClient as unknown as IJMAPClient);
+      expect(useFilterStore.getState().availableAccounts).toHaveLength(2);
+      expect(useFilterStore.getState().selectedAccountId).toBe('primary');
+    });
+  });
+
+  describe('selectAccount', () => {
+    it('re-fetches scripts for the chosen account id', async () => {
+      const fetchedFor: (string | undefined)[] = [];
+      const mockClient = {
+        getSieveAccountId: () => 'primary',
+        getSieveAccounts: () => [
+          { id: 'primary', name: 'Me', isPrimary: true },
+          { id: 'group', name: 'Sales', isPrimary: false },
+        ],
+        getSieveCapabilities: () => null,
+        getSieveScripts: async (accountId?: string) => {
+          fetchedFor.push(accountId);
+          return [];
+        },
+      };
+      // Seed some primary-account state to confirm it gets cleared on switch.
+      useFilterStore.setState({ rules: [makeRule()], activeScriptId: 'old', isOpaque: true });
+
+      await useFilterStore.getState().selectAccount(mockClient as unknown as IJMAPClient, 'group');
+
+      expect(useFilterStore.getState().selectedAccountId).toBe('group');
+      expect(fetchedFor).toContain('group');
+      expect(useFilterStore.getState().rules).toEqual([]);
+      expect(useFilterStore.getState().isOpaque).toBe(false);
+    });
+  });
+
+  describe('account threading', () => {
+    it('passes the selected account id to update and validate', async () => {
+      const calls: Array<{ method: string; args: unknown[] }> = [];
+      const mockClient = {
+        updateSieveScript: async (...args: unknown[]) => { calls.push({ method: 'updateSieveScript', args }); },
+        createSieveScript: async (...args: unknown[]) => { calls.push({ method: 'createSieveScript', args }); return { id: 'x' }; },
+        validateSieveScript: async (...args: unknown[]) => { calls.push({ method: 'validateSieveScript', args }); return { isValid: true }; },
+      };
+      useFilterStore.setState({
+        activeScriptId: 'existing-id',
+        rules: [makeRule()],
+        isOpaque: false,
+        selectedAccountId: 'group',
+      });
+
+      await useFilterStore.getState().saveFilters(mockClient as unknown as IJMAPClient);
+      await useFilterStore.getState().validateScript(mockClient as unknown as IJMAPClient, 'require "fileinto";');
+
+      const update = calls.find(c => c.method === 'updateSieveScript');
+      const validate = calls.find(c => c.method === 'validateSieveScript');
+      expect(update?.args[3]).toBe('group');
+      expect(validate?.args[1]).toBe('group');
+    });
   });
 });

stores/__tests__/managed-account-store.test.ts

@@ -0,0 +1,38 @@
+import { describe, it, expect, beforeEach } from 'vitest';
+import { useManagedAccountStore } from '../managed-account-store';
+import type { SharedAccount } from '@/lib/jmap/types';
+
+const sharedAccount: SharedAccount = {
+  id: 'group-1',
+  name: 'Sales',
+  isPrimary: false,
+  capabilities: { mail: true, sieve: true, calendars: true, contacts: true, filenode: false },
+};
+
+describe('managed-account-store', () => {
+  beforeEach(() => {
+    useManagedAccountStore.getState().clear();
+  });
+
+  it('defaults to no managed account (own account)', () => {
+    expect(useManagedAccountStore.getState().managedAccountId).toBeNull();
+    expect(useManagedAccountStore.getState().managedAccount).toBeNull();
+  });
+
+  it('setManagedAccount enters scoped mode for the account', () => {
+    useManagedAccountStore.getState().setManagedAccount(sharedAccount);
+    expect(useManagedAccountStore.getState().managedAccountId).toBe('group-1');
+    expect(useManagedAccountStore.getState().managedAccount).toEqual(sharedAccount);
+  });
+
+  it('setManagedAccount(null) and clear() return to the own account', () => {
+    useManagedAccountStore.getState().setManagedAccount(sharedAccount);
+    useManagedAccountStore.getState().setManagedAccount(null);
+    expect(useManagedAccountStore.getState().managedAccountId).toBeNull();
+    expect(useManagedAccountStore.getState().managedAccount).toBeNull();
+
+    useManagedAccountStore.getState().setManagedAccount(sharedAccount);
+    useManagedAccountStore.getState().clear();
+    expect(useManagedAccountStore.getState().managedAccountId).toBeNull();
+  });
+});

stores/filter-store.ts

@@ -5,6 +5,12 @@ import { parseScript } from '@/lib/sieve/parser';
 import { generateScript } from '@/lib/sieve/generator';
 import { debug } from '@/lib/debug';
 
+interface SieveAccount {
+  id: string;
+  name: string;
+  isPrimary: boolean;
+}
+
 interface FilterStore {
   rules: FilterRule[];
   isLoading: boolean;
@@ -17,9 +23,12 @@ interface FilterStore {
   rawScript: string;
   vacationSettings: VacationSieveConfig | null;
   externalRequires: string[];
+  availableAccounts: SieveAccount[];
+  selectedAccountId: string | null;
 
   setSupported: (supported: boolean) => void;
-  fetchFilters: (client: IJMAPClient) => Promise<void>;
+  fetchFilters: (client: IJMAPClient, accountId?: string) => Promise<void>;
+  selectAccount: (client: IJMAPClient, accountId: string) => Promise<void>;
   saveFilters: (client: IJMAPClient) => Promise<void>;
   validateScript: (client: IJMAPClient, content: string) => Promise<{ isValid: boolean; errors?: string[] }>;
   addRule: (rule: FilterRule) => void;
@@ -44,16 +53,23 @@ export const useFilterStore = create<FilterStore>()((set, get) => ({
   rawScript: '',
   vacationSettings: null,
   externalRequires: [],
+  availableAccounts: [],
+  selectedAccountId: null,
 
   setSupported: (supported) => set({ isSupported: supported }),
 
-  fetchFilters: async (client) => {
+  fetchFilters: async (client, accountId) => {
     set({ isLoading: true, error: null });
     try {
-      const capabilities = client.getSieveCapabilities();
+      const accounts = client.getSieveAccounts();
+      const resolvedId =
+        accountId || get().selectedAccountId || client.getSieveAccountId();
+      set({ availableAccounts: accounts, selectedAccountId: resolvedId });
+
+      const capabilities = client.getSieveCapabilities(resolvedId);
       set({ sieveCapabilities: capabilities });
 
-      const allScripts = await client.getSieveScripts();
+      const allScripts = await client.getSieveScripts(resolvedId);
       debug.log('filters', 'Sieve scripts fetched:', allScripts.length);
 
       // Skip the server-managed 'vacation' script (RFC 9661 §4) - it can only
@@ -68,7 +84,7 @@ export const useFilterStore = create<FilterStore>()((set, get) => ({
 
       set({ activeScriptId: activeScript.id });
 
-      const content = await client.getSieveScriptContent(activeScript.blobId);
+      const content = await client.getSieveScriptContent(activeScript.blobId, resolvedId);
       set({ rawScript: content });
 
       const result = parseScript(content);
@@ -101,10 +117,25 @@ export const useFilterStore = create<FilterStore>()((set, get) => ({
     }
   },
 
+  selectAccount: async (client, accountId) => {
+    // Reset parsed state so one account's rules/script never leak into another
+    // before the re-fetch populates the new account's data.
+    set({
+      selectedAccountId: accountId,
+      rules: [],
+      rawScript: '',
+      activeScriptId: null,
+      isOpaque: false,
+      vacationSettings: null,
+      externalRequires: [],
+    });
+    await get().fetchFilters(client, accountId);
+  },
+
   saveFilters: async (client) => {
     set({ isSaving: true, error: null });
     try {
-      const { isOpaque, rawScript, rules, activeScriptId, vacationSettings, externalRequires } = get();
+      const { isOpaque, rawScript, rules, activeScriptId, vacationSettings, externalRequires, selectedAccountId } = get();
 
       let content: string;
       if (isOpaque) {
@@ -114,9 +145,9 @@ export const useFilterStore = create<FilterStore>()((set, get) => ({
       }
 
       if (activeScriptId) {
-        await client.updateSieveScript(activeScriptId, content, true);
+        await client.updateSieveScript(activeScriptId, content, true, selectedAccountId || undefined);
       } else {
-        const script = await client.createSieveScript('filters', content, true);
+        const script = await client.createSieveScript('filters', content, true, selectedAccountId || undefined);
         set({ activeScriptId: script.id });
       }
 
@@ -133,7 +164,7 @@ export const useFilterStore = create<FilterStore>()((set, get) => ({
   },
 
   validateScript: async (client, content) => {
-    return client.validateSieveScript(content);
+    return client.validateSieveScript(content, get().selectedAccountId || undefined);
   },
 
   addRule: (rule) => {
@@ -204,5 +235,7 @@ export const useFilterStore = create<FilterStore>()((set, get) => ({
     rawScript: '',
     vacationSettings: null,
     externalRequires: [],
+    availableAccounts: [],
+    selectedAccountId: null,
   }),
 }));

stores/managed-account-store.ts

@@ -0,0 +1,32 @@
+import { create } from 'zustand';
+import type { SharedAccount } from '@/lib/jmap/types';
+
+/**
+ * Tracks which account the settings panel is currently scoped to. `null` means
+ * the user's own (primary) account — the default, full settings view. When set
+ * to a shared/group account, the settings panel enters "scoped mode": a reduced
+ * tab list and a "Managing: <name>" header, and the account-scoped settings
+ * pages (filters, vacation, calendars, contacts) read `managedAccountId` to
+ * target that account.
+ *
+ * This is session-only navigation state (not persisted) so a shared-account
+ * context never leaks across reloads or logout.
+ */
+interface ManagedAccountStore {
+  managedAccountId: string | null;
+  managedAccount: SharedAccount | null;
+
+  /** Enter scoped mode for `account`, or pass `null` to return to own account. */
+  setManagedAccount: (account: SharedAccount | null) => void;
+  clear: () => void;
+}
+
+export const useManagedAccountStore = create<ManagedAccountStore>()((set) => ({
+  managedAccountId: null,
+  managedAccount: null,
+
+  setManagedAccount: (account) =>
+    set({ managedAccountId: account?.id ?? null, managedAccount: account }),
+
+  clear: () => set({ managedAccountId: null, managedAccount: null }),
+}));

stores/vacation-store.ts

@@ -13,7 +13,7 @@ interface VacationStore {
   error: string | null;
   isSupported: boolean;
 
-  fetchVacationResponse: (client: IJMAPClient) => Promise<void>;
+  fetchVacationResponse: (client: IJMAPClient, accountId?: string) => Promise<void>;
   updateVacationResponse: (client: IJMAPClient, updates: {
     isEnabled?: boolean;
     fromDate?: string | null;
@@ -21,7 +21,7 @@ interface VacationStore {
     subject?: string;
     textBody?: string;
     htmlBody?: string | null;
-  }) => Promise<void>;
+  }, accountId?: string) => Promise<void>;
   setSupported: (supported: boolean) => void;
   clearState: () => void;
 }
@@ -38,10 +38,10 @@ export const useVacationStore = create<VacationStore>()((set) => ({
   error: null,
   isSupported: false,
 
-  fetchVacationResponse: async (client) => {
+  fetchVacationResponse: async (client, accountId) => {
     set({ isLoading: true, error: null });
     try {
-      const vacation = await client.getVacationResponse();
+      const vacation = await client.getVacationResponse(accountId);
       set({
         isEnabled: vacation.isEnabled,
         fromDate: vacation.fromDate,
@@ -59,10 +59,10 @@ export const useVacationStore = create<VacationStore>()((set) => ({
     }
   },
 
-  updateVacationResponse: async (client, updates) => {
+  updateVacationResponse: async (client, updates, accountId) => {
     set({ isSaving: true, error: null });
     try {
-      await client.setVacationResponse(updates);
+      await client.setVacationResponse(updates, accountId);
       set((state) => ({
         ...state,
         ...updates,