feat: implement tagging functionality for emails with drag-and-drop support

app/[locale]/page.tsx

@@ -105,6 +105,8 @@ export default function Home() {
     clearSearchFilters,
     toggleAdvancedSearch,
     advancedSearch,
+    selectedKeyword,
+    selectKeyword,
   } = useEmailStore();
 
   // Keyboard shortcuts handlers
@@ -594,6 +596,25 @@ export default function Home() {
     }
   };
 
+  const handleTagSelect = async (keywordId: string | null) => {
+    selectKeyword(keywordId);
+
+    // On mobile, close sidebar and go to list view
+    if (isMobile) {
+      setSidebarOpen(false);
+      setActiveView("list");
+    }
+
+    // On tablet, show the list again
+    if (isTablet) {
+      setTabletListVisible(true);
+    }
+
+    if (client) {
+      await fetchEmails(client);
+    }
+  };
+
   const handleLogout = () => {
     logout();
     router.push('/login');
@@ -852,7 +873,9 @@ export default function Home() {
             <Sidebar
               mailboxes={mailboxes}
               selectedMailbox={selectedMailbox}
+              selectedKeyword={selectedKeyword}
               onMailboxSelect={handleMailboxSelect}
+              onTagSelect={handleTagSelect}
               onCompose={() => {
                 setComposerMode('compose');
                 setShowComposer(true);

app/api/dev-jmap/[...path]/route.ts

@@ -119,7 +119,7 @@ const emails: MockEmail[] = [
     },
   },
   {
-    id: 'email-002', threadId: 'thread-002', mailboxIds: { 'mb-inbox': true }, keywords: { $seen: true, $flagged: true }, size: 5100, receivedAt: daysAgo(1),
+    id: 'email-002', threadId: 'thread-002', mailboxIds: { 'mb-inbox': true }, keywords: { $seen: true, $flagged: true, '$label:blue': true }, size: 5100, receivedAt: daysAgo(1),
     from: [{ name: 'Pierre Dubois', email: 'pierre@dubois.example' }],
     to: [{ name: 'Dev User', email: 'dev@localhost' }],
     cc: [{ name: 'Karel de Vries', email: 'karel@devries.example' }],
@@ -151,7 +151,7 @@ const emails: MockEmail[] = [
     },
   },
   {
-    id: 'email-004', threadId: 'thread-004', mailboxIds: { 'mb-inbox': true }, keywords: {}, size: 6200, receivedAt: daysAgo(0),
+    id: 'email-004', threadId: 'thread-004', mailboxIds: { 'mb-inbox': true }, keywords: { '$label:red': true }, size: 6200, receivedAt: daysAgo(0),
     from: [{ name: 'GitHub Notifications', email: 'notifications@github.com' }],
     to: [{ name: 'Dev User', email: 'dev@localhost' }], cc: [],
     subject: '[jmap-webmail] New issue: Add dark mode toggle (#42)',
@@ -180,7 +180,7 @@ const emails: MockEmail[] = [
   },
   // Newsletter with full HTML
   {
-    id: 'email-013', threadId: 'thread-012', mailboxIds: { 'mb-inbox': true }, keywords: {}, size: 18200, receivedAt: daysAgo(0),
+    id: 'email-013', threadId: 'thread-012', mailboxIds: { 'mb-inbox': true }, keywords: { '$label:purple': true }, size: 18200, receivedAt: daysAgo(0),
     from: [{ name: 'Launchpad Weekly', email: 'hello@launchpad.example' }],
     to: [{ name: 'Dev User', email: 'dev@localhost' }], cc: [],
     subject: 'Launchpad Weekly #47 — The future of the open web',
@@ -227,7 +227,7 @@ const emails: MockEmail[] = [
     ],
   },
   {
-    id: 'email-016', threadId: 'thread-015', mailboxIds: { 'mb-inbox': true }, keywords: {}, size: 4100, receivedAt: hoursAgo(3),
+    id: 'email-016', threadId: 'thread-015', mailboxIds: { 'mb-inbox': true }, keywords: { '$label:green': true }, size: 4100, receivedAt: hoursAgo(3),
     from: [{ name: 'Élise Moreau', email: 'elise.moreau@fjord-systems.example' }],
     to: [{ name: 'Dev User', email: 'dev@localhost' }], cc: [],
     subject: 'Code review request: JMAP-342 contact import',
@@ -254,7 +254,7 @@ const emails: MockEmail[] = [
     },
   },
   {
-    id: 'email-018', threadId: 'thread-017', mailboxIds: { 'mb-inbox': true }, keywords: { $seen: true, $flagged: true }, size: 4700, receivedAt: daysAgo(1),
+    id: 'email-018', threadId: 'thread-017', mailboxIds: { 'mb-inbox': true }, keywords: { $seen: true, $flagged: true, '$label:orange': true }, size: 4700, receivedAt: daysAgo(1),
     from: [{ name: 'Hetzner Cloud', email: 'billing@hetzner.example' }],
     to: [{ name: 'Dev User', email: 'dev@localhost' }], cc: [],
     subject: 'Your Hetzner invoice is available — February 2026',
@@ -354,7 +354,7 @@ const emails: MockEmail[] = [
     },
   },
   {
-    id: 'email-025', threadId: 'thread-024', mailboxIds: { 'mb-inbox': true }, keywords: { $seen: true, $flagged: true }, size: 4100, receivedAt: daysAgo(6),
+    id: 'email-025', threadId: 'thread-024', mailboxIds: { 'mb-inbox': true }, keywords: { $seen: true, $flagged: true, '$label:blue': true }, size: 4100, receivedAt: daysAgo(6),
     from: [{ name: 'Stripe Developer', email: 'developer-updates@stripe.example' }],
     to: [{ name: 'Dev User', email: 'dev@localhost' }], cc: [],
     subject: 'Action required: API v2023-10 deprecation on April 15, 2026',
@@ -1302,23 +1302,76 @@ function handleMailboxSet(args: MethodArgs, callId: string): MethodResult {
 }
 
 function handleEmailQuery(args: MethodArgs, callId: string): MethodResult {
-  const filter = args.filter as Record<string, string> | undefined;
+  const filter = args.filter as Record<string, unknown> | undefined;
   const limit = (args.limit as number) || 50;
   const position = (args.position as number) || 0;
 
   let filtered = [...emails];
-  if (filter?.inMailbox) {
-    filtered = filtered.filter((e) => e.mailboxIds[filter.inMailbox]);
+
+  // Support both flat filters and operator/conditions compound filters
+  const applyFilter = (f: Record<string, unknown>, list: MockEmail[]): MockEmail[] => {
+    let result = list;
+    if (f.operator && Array.isArray(f.conditions)) {
+      const sub = (f.conditions as Record<string, unknown>[]).map(c => applyFilter(c, result));
+      if (f.operator === 'AND') {
+        result = sub.reduce((acc, s) => acc.filter(e => s.includes(e)));
+      } else if (f.operator === 'OR') {
+        const ids = new Set(sub.flat().map(e => e.id));
+        result = result.filter(e => ids.has(e.id));
       }
-  if (filter?.text) {
-    const q = (filter.text as string).toLowerCase();
-    filtered = filtered.filter(
+      return result;
+    }
+    if (f.inMailbox) {
+      result = result.filter((e) => e.mailboxIds[f.inMailbox as string]);
+    }
+    if (f.text) {
+      const q = (f.text as string).toLowerCase();
+      result = result.filter(
         (e) =>
           (e.subject?.toLowerCase().includes(q)) ||
           (e.preview?.toLowerCase().includes(q)) ||
-        e.from?.some((f) => f.name?.toLowerCase().includes(q) || f.email.toLowerCase().includes(q)),
+          e.from?.some((addr) => addr.name?.toLowerCase().includes(q) || addr.email.toLowerCase().includes(q)),
       );
     }
+    if (f.hasKeyword) {
+      const kw = f.hasKeyword as string;
+      result = result.filter((e) => e.keywords[kw] === true);
+    }
+    if (f.notKeyword) {
+      const kw = f.notKeyword as string;
+      result = result.filter((e) => !e.keywords[kw]);
+    }
+    if (f.from) {
+      const q = (f.from as string).toLowerCase();
+      result = result.filter((e) => e.from?.some((addr) => addr.name?.toLowerCase().includes(q) || addr.email.toLowerCase().includes(q)));
+    }
+    if (f.to) {
+      const q = (f.to as string).toLowerCase();
+      result = result.filter((e) => e.to?.some((addr) => addr.name?.toLowerCase().includes(q) || addr.email.toLowerCase().includes(q)));
+    }
+    if (f.subject) {
+      const q = (f.subject as string).toLowerCase();
+      result = result.filter((e) => e.subject?.toLowerCase().includes(q));
+    }
+    if (f.hasAttachment === true) {
+      result = result.filter((e) => e.hasAttachment);
+    } else if (f.hasAttachment === false) {
+      result = result.filter((e) => !e.hasAttachment);
+    }
+    if (f.after) {
+      const after = new Date(f.after as string).getTime();
+      result = result.filter((e) => new Date(e.receivedAt).getTime() >= after);
+    }
+    if (f.before) {
+      const before = new Date(f.before as string).getTime();
+      result = result.filter((e) => new Date(e.receivedAt).getTime() <= before);
+    }
+    return result;
+  };
+
+  if (filter) {
+    filtered = applyFilter(filter, filtered);
+  }
 
   // Sort newest first
   filtered.sort((a, b) => new Date(b.receivedAt).getTime() - new Date(a.receivedAt).getTime());
@@ -1377,9 +1430,14 @@ function handleEmailSet(args: MethodArgs, callId: string): MethodResult {
         email.mailboxIds = changes.mailboxIds as Record<string, boolean>;
       }
 
-      // Full keywords replacement
+      // Full keywords replacement (strip false values per JMAP spec: keywords is a set)
       if (changes.keywords !== undefined) {
-        email.keywords = changes.keywords as Record<string, boolean>;
+        const raw = changes.keywords as Record<string, boolean>;
+        const cleaned: Record<string, boolean> = {};
+        for (const [k, v] of Object.entries(raw)) {
+          if (v) cleaned[k] = true;
+        }
+        email.keywords = cleaned;
       }
 
       // Patch-style keyword updates: "keywords/$seen", "keywords/$flagged", etc.

components/layout/sidebar.tsx

@@ -23,21 +23,26 @@ import {
   Palmtree,
   Settings,
   X,
+  Tag,
 } from "lucide-react";
 import { cn, buildMailboxTree, MailboxNode } from "@/lib/utils";
 import { Mailbox } from "@/lib/jmap/types";
 import { useDragDropContext } from "@/contexts/drag-drop-context";
 import { useMailboxDrop } from "@/hooks/use-mailbox-drop";
+import { useTagDrop } from "@/hooks/use-tag-drop";
 import { useUIStore } from "@/stores/ui-store";
 import { useAuthStore } from "@/stores/auth-store";
 import { useVacationStore } from "@/stores/vacation-store";
+import { useSettingsStore, KEYWORD_PALETTE, KeywordDefinition } from "@/stores/settings-store";
 import { toast } from "@/stores/toast-store";
 import { debug } from "@/lib/debug";
 
 interface SidebarProps {
   mailboxes: Mailbox[];
   selectedMailbox?: string;
+  selectedKeyword?: string | null;
   onMailboxSelect?: (mailboxId: string) => void;
+  onTagSelect?: (keywordId: string | null) => void;
   onCompose?: () => void;
   onSidebarClose?: () => void;
   className?: string;
@@ -217,6 +222,62 @@ function MailboxTreeItem({
   );
 }
 
+function TagItem({
+  kw,
+  isSelected,
+  isCollapsed,
+  onTagSelect,
+}: {
+  kw: KeywordDefinition;
+  isSelected: boolean;
+  isCollapsed: boolean;
+  onTagSelect?: (keywordId: string | null) => void;
+}) {
+  const t = useTranslations('notifications');
+  const palette = KEYWORD_PALETTE[kw.color];
+  const { isDragging: globalDragging } = useDragDropContext();
+  const { dropHandlers, isValidDropTarget } = useTagDrop({
+    tagId: kw.id,
+    onSuccess: (count, _tagLabel) => {
+      if (count === 1) {
+        toast.success(t('email_tagged'), kw.label);
+      } else {
+        toast.success(t('emails_tagged', { count }), kw.label);
+      }
+    },
+    onError: () => {
+      toast.error(t('tag_failed'), kw.label);
+    },
+  });
+
+  return (
+    <div
+      {...(globalDragging ? dropHandlers : {})}
+      className={cn(
+        "group w-full flex items-center py-1 lg:py-1 max-lg:py-3 max-lg:min-h-[44px] text-sm transition-all duration-200",
+        isCollapsed ? "justify-center px-1" : "px-2",
+        isSelected
+          ? "bg-accent text-accent-foreground"
+          : "hover:bg-muted text-foreground",
+        isValidDropTarget && "bg-primary/20 ring-2 ring-primary ring-inset"
+      )}
+    >
+      <button
+        onClick={() => onTagSelect?.(isSelected ? null : kw.id)}
+        className={cn(
+          "flex items-center py-1 lg:py-1 max-lg:py-2 px-1 rounded transition-colors duration-150",
+          isCollapsed ? "justify-center" : "flex-1 text-left"
+        )}
+        style={isCollapsed ? undefined : { paddingLeft: '40px' }}
+        title={isCollapsed ? kw.label : undefined}
+      >
+        <span className={cn("w-3 h-3 rounded-full flex-shrink-0", palette?.dot || "bg-gray-400", !isCollapsed && "mr-2")} />
+        {!isCollapsed && <span className="truncate">{kw.label}</span>}
+      </button>
+    </div>
+  );
+}
+
 function VacationBanner() {
   const t = useTranslations('sidebar');
   const router = useRouter();
@@ -243,7 +304,9 @@ function VacationBanner() {
 export function Sidebar({
   mailboxes = [],
   selectedMailbox = "",
+  selectedKeyword = null,
   onMailboxSelect,
+  onTagSelect,
   onCompose,
   onSidebarClose,
   className,
@@ -251,6 +314,13 @@ export function Sidebar({
   const { sidebarCollapsed: isCollapsed, toggleSidebarCollapsed } = useUIStore();
   const { primaryIdentity } = useAuthStore();
   const [expandedFolders, setExpandedFolders] = useState<Set<string>>(new Set());
+  const [tagsExpanded, setTagsExpanded] = useState(() => {
+    try {
+      const stored = localStorage.getItem('sidebarTagsExpanded');
+      return stored !== null ? JSON.parse(stored) : true;
+    } catch { return true; }
+  });
+  const emailKeywords = useSettingsStore(s => s.emailKeywords);
   const t = useTranslations('sidebar');
 
   useEffect(() => {
@@ -379,7 +449,7 @@ export function Sidebar({
                 <MailboxTreeItem
                   key={node.id}
                   node={node}
-                  selectedMailbox={selectedMailbox}
+                  selectedMailbox={selectedKeyword ? "" : selectedMailbox}
                   expandedFolders={expandedFolders}
                   onMailboxSelect={onMailboxSelect}
                   onToggleExpand={handleToggleExpand}
@@ -389,6 +459,86 @@ export function Sidebar({
             </>
           )}
         </div>
+
+        {/* Tags Section */}
+        {emailKeywords.length > 0 && (
+          <>
+            <div
+              className={cn(
+                "group w-full flex items-center py-1 lg:py-1 max-lg:py-3 max-lg:min-h-[44px] text-sm transition-all duration-200 font-medium",
+                isCollapsed ? "justify-center px-1" : "px-2",
+                "text-foreground hover:bg-muted"
+              )}
+            >
+              {!isCollapsed && (
+                <button
+                  onClick={() => {
+                    setTagsExpanded((prev: boolean) => {
+                      const next = !prev;
+                      try { localStorage.setItem('sidebarTagsExpanded', JSON.stringify(next)); } catch { /* */ }
+                      return next;
+                    });
+                  }}
+                  className={cn(
+                    "p-0.5 rounded mr-1 transition-all duration-200",
+                    "hover:bg-muted active:bg-accent"
+                  )}
+                  title={tagsExpanded ? t('collapse_tooltip') : t('expand_tooltip')}
+                >
+                  {tagsExpanded ? (
+                    <ChevronDown className="w-3 h-3 text-muted-foreground" />
+                  ) : (
+                    <ChevronRight className="w-3 h-3 text-muted-foreground" />
+                  )}
+                </button>
+              )}
+
+              <button
+                onClick={() => {
+                  if (isCollapsed) return;
+                  setTagsExpanded((prev: boolean) => {
+                    const next = !prev;
+                    try { localStorage.setItem('sidebarTagsExpanded', JSON.stringify(next)); } catch { /* */ }
+                    return next;
+                  });
+                }}
+                className={cn(
+                  "flex items-center py-1 lg:py-1 max-lg:py-2 px-1 rounded",
+                  "transition-colors duration-150",
+                  isCollapsed ? "justify-center" : "flex-1 text-left"
+                )}
+                style={isCollapsed ? undefined : { paddingLeft: '4px' }}
+                title={isCollapsed ? t("tags") : undefined}
+              >
+                <Tag className={cn(
+                  "w-4 h-4 flex-shrink-0 transition-colors",
+                  !isCollapsed && "mr-2",
+                  tagsExpanded && "text-primary"
+                )} />
+                {!isCollapsed && (
+                  <span className="flex-1 truncate">{t("tags")}</span>
+                )}
+              </button>
+            </div>
+
+            {((tagsExpanded && !isCollapsed) || isCollapsed) && (
+              <div className="relative">
+                {emailKeywords.map((kw) => {
+                  const isSelected = selectedKeyword === kw.id;
+                  return (
+                    <TagItem
+                      key={kw.id}
+                      kw={kw}
+                      isSelected={isSelected}
+                      isCollapsed={isCollapsed}
+                      onTagSelect={onTagSelect}
+                    />
+                  );
+                })}
+              </div>
+            )}
+          </>
+        )}
       </div>
 
       {/* Compose Button */}

hooks/use-tag-drop.ts

@@ -0,0 +1,115 @@
+"use client";
+
+import { useCallback, useState, DragEvent } from "react";
+import { useEmailStore } from "@/stores/email-store";
+import { useAuthStore } from "@/stores/auth-store";
+import { useDragDropContext } from "@/contexts/drag-drop-context";
+
+interface UseTagDropOptions {
+  tagId: string;
+  onSuccess?: (count: number, tagLabel: string) => void;
+  onError?: (error: string) => void;
+}
+
+interface UseTagDropReturn {
+  dropHandlers: {
+    onDragOver: (e: DragEvent<HTMLDivElement>) => void;
+    onDragEnter: (e: DragEvent<HTMLDivElement>) => void;
+    onDragLeave: (e: DragEvent<HTMLDivElement>) => void;
+    onDrop: (e: DragEvent<HTMLDivElement>) => void;
+  };
+  isDropTarget: boolean;
+  isValidDropTarget: boolean;
+}
+
+export function useTagDrop({ tagId, onSuccess, onError }: UseTagDropOptions): UseTagDropReturn {
+  const [isOver, setIsOver] = useState(false);
+  const { client } = useAuthStore();
+  const { fetchEmails, selectedMailbox } = useEmailStore();
+  const { isDragging, endDrag } = useDragDropContext();
+
+  const handleDragOver = useCallback((e: DragEvent<HTMLDivElement>) => {
+    e.preventDefault();
+    if (isDragging) {
+      e.dataTransfer.dropEffect = "copy";
+    } else {
+      e.dataTransfer.dropEffect = "none";
+    }
+  }, [isDragging]);
+
+  const handleDragEnter = useCallback((e: DragEvent<HTMLDivElement>) => {
+    e.preventDefault();
+    e.stopPropagation();
+    setIsOver(true);
+  }, []);
+
+  const handleDragLeave = useCallback((e: DragEvent<HTMLDivElement>) => {
+    e.preventDefault();
+    e.stopPropagation();
+    const relatedTarget = e.relatedTarget as Node | null;
+    if (!e.currentTarget.contains(relatedTarget)) {
+      setIsOver(false);
+    }
+  }, []);
+
+  const handleDrop = useCallback(async (e: DragEvent<HTMLDivElement>) => {
+    e.preventDefault();
+    e.stopPropagation();
+    setIsOver(false);
+
+    if (!client || !isDragging) {
+      endDrag();
+      return;
+    }
+
+    try {
+      const emailIdsJson = e.dataTransfer.getData("application/x-email-ids");
+      if (!emailIdsJson) {
+        endDrag();
+        return;
+      }
+
+      const emailIds: string[] = JSON.parse(emailIdsJson);
+
+      for (const emailId of emailIds) {
+        // Read fresh state to avoid stale closures
+        const currentEmails = useEmailStore.getState().emails;
+        const email = currentEmails.find(em => em.id === emailId);
+        const keywords = { ...(email?.keywords || {}) };
+
+        // Remove old label/color keywords
+        Object.keys(keywords).forEach(key => {
+          if (key.startsWith("$label:") || key.startsWith("$color:")) {
+            keywords[key] = false;
+          }
+        });
+
+        // Add the new tag
+        keywords[`$label:${tagId}`] = true;
+
+        await client.updateEmailKeywords(emailId, keywords);
+      }
+
+      // Refresh the email list
+      await fetchEmails(client, selectedMailbox);
+
+      onSuccess?.(emailIds.length, tagId);
+    } catch (error) {
+      console.error("Failed to tag emails:", error);
+      onError?.(error instanceof Error ? error.message : "Unknown error");
+    } finally {
+      endDrag();
+    }
+  }, [client, isDragging, tagId, fetchEmails, selectedMailbox, endDrag, onSuccess, onError]);
+
+  return {
+    dropHandlers: {
+      onDragOver: handleDragOver,
+      onDragEnter: handleDragEnter,
+      onDragLeave: handleDragLeave,
+      onDrop: handleDrop,
+    },
+    isDropTarget: isOver && isDragging,
+    isValidDropTarget: isOver && isDragging,
+  };
+}

lib/jmap/client.ts

@@ -499,13 +499,16 @@ export class JMAPClient {
     }
   }
 
-  async getEmails(mailboxId?: string, accountId?: string, limit: number = 50, position: number = 0): Promise<{ emails: Email[], hasMore: boolean, total: number }> {
+  async getEmails(mailboxId?: string, accountId?: string, limit: number = 50, position: number = 0, hasKeyword?: string): Promise<{ emails: Email[], hasMore: boolean, total: number }> {
     try {
       const targetAccountId = accountId || this.accountId;
-      const filter: { inMailbox?: string } = {};
+      const filter: { inMailbox?: string; hasKeyword?: string } = {};
       if (mailboxId) {
         filter.inMailbox = mailboxId;
       }
+      if (hasKeyword) {
+        filter.hasKeyword = hasKeyword;
+      }
 
       const response = await this.request([
         ["Email/query", {

locales/de/common.json

@@ -91,6 +91,7 @@
     },
     "clear_search": "Suche löschen",
     "vacation_active": "Abwesenheitsnotiz ist aktiv",
+    "tags": "Tags",
     "compose_hint": "Verfassen (c)",
     "search_placeholder_hint": "E-Mails suchen... (drücke /)",
     "mail": "E-Mail",
@@ -377,6 +378,9 @@
     "moved_to_mailbox": "Nach {mailbox} verschoben",
     "move_failed": "Verschieben fehlgeschlagen",
     "move_error": "E-Mails konnten nicht in den ausgewählten Ordner verschoben werden",
+    "email_tagged": "E-Mail markiert",
+    "emails_tagged": "{count} E-Mails markiert",
+    "tag_failed": "Markierung fehlgeschlagen",
     "identity_created": "Identität erfolgreich erstellt",
     "identity_updated": "Identität erfolgreich aktualisiert",
     "identity_deleted": "Identität gelöscht",

locales/en/common.json

@@ -94,6 +94,7 @@
     },
     "clear_search": "Clear search",
     "vacation_active": "Vacation responder is active",
+    "tags": "Tags",
     "mail": "Mail",
     "nav_label": "Navigation"
   },
@@ -388,6 +389,9 @@
     "moved_to_mailbox": "Moved to {mailbox}",
     "move_failed": "Move failed",
     "move_error": "Could not move emails to the selected folder",
+    "email_tagged": "Email tagged",
+    "emails_tagged": "{count} emails tagged",
+    "tag_failed": "Tagging failed",
     "identity_created": "Identity created successfully",
     "identity_updated": "Identity updated successfully",
     "identity_deleted": "Identity deleted",

locales/es/common.json

@@ -91,6 +91,7 @@
     },
     "clear_search": "Limpiar búsqueda",
     "vacation_active": "Respuesta automática activa",
+    "tags": "Etiquetas",
     "compose_hint": "Redactar (c)",
     "search_placeholder_hint": "Buscar correo... (pulsa /)",
     "mail": "Correo",
@@ -377,6 +378,9 @@
     "moved_to_mailbox": "Movido a {mailbox}",
     "move_failed": "Error al mover",
     "move_error": "No se pudieron mover los correos a la carpeta seleccionada",
+    "email_tagged": "Correo etiquetado",
+    "emails_tagged": "{count} correos etiquetados",
+    "tag_failed": "Error al etiquetar",
     "identity_created": "Identidad creada exitosamente",
     "identity_updated": "Identidad actualizada exitosamente",
     "identity_deleted": "Identidad eliminada",

locales/fr/common.json

@@ -93,6 +93,7 @@
     },
     "clear_search": "Effacer la recherche",
     "vacation_active": "Répondeur d'absence activé",
+    "tags": "Étiquettes",
     "mail": "Messagerie",
     "nav_label": "Navigation"
   },
@@ -377,6 +378,9 @@
     "moved_to_mailbox": "Déplacé vers {mailbox}",
     "move_failed": "Échec du déplacement",
     "move_error": "Impossible de déplacer les emails vers le dossier sélectionné",
+    "email_tagged": "E-mail étiqueté",
+    "emails_tagged": "{count} e-mails étiquetés",
+    "tag_failed": "Échec de l'étiquetage",
     "identity_created": "Identité créée avec succès",
     "identity_updated": "Identité mise à jour avec succès",
     "identity_deleted": "Identité supprimée",

locales/it/common.json

@@ -91,6 +91,7 @@
     },
     "clear_search": "Cancella ricerca",
     "vacation_active": "Risponditore automatico attivo",
+    "tags": "Etichette",
     "compose_hint": "Scrivi (c)",
     "search_placeholder_hint": "Cerca posta... (premi /)",
     "mail": "Posta",
@@ -377,6 +378,9 @@
     "moved_to_mailbox": "Spostato in {mailbox}",
     "move_failed": "Spostamento non riuscito",
     "move_error": "Impossibile spostare i messaggi nella cartella selezionata",
+    "email_tagged": "Email etichettata",
+    "emails_tagged": "{count} email etichettate",
+    "tag_failed": "Etichettatura fallita",
     "identity_created": "Identità creata con successo",
     "identity_updated": "Identità aggiornata con successo",
     "identity_deleted": "Identità eliminata",

locales/ja/common.json

@@ -93,6 +93,7 @@
     },
     "clear_search": "検索をクリア",
     "vacation_active": "不在応答が有効です",
+    "tags": "タグ",
     "mail": "メール",
     "nav_label": "ナビゲーション"
   },
@@ -377,6 +378,9 @@
     "moved_to_mailbox": "{mailbox}に移動しました",
     "move_failed": "移動に失敗しました",
     "move_error": "選択したフォルダにメールを移動できませんでした",
+    "email_tagged": "メールにタグを付けました",
+    "emails_tagged": "{count}件のメールにタグを付けました",
+    "tag_failed": "タグ付けに失敗しました",
     "identity_created": "送信者情報を作成しました",
     "identity_updated": "送信者情報を更新しました",
     "identity_deleted": "送信者情報を削除しました",

locales/nl/common.json

@@ -91,6 +91,7 @@
     },
     "clear_search": "Zoekopdracht wissen",
     "vacation_active": "Afwezigheidsmelder is actief",
+    "tags": "Labels",
     "compose_hint": "Opstellen (c)",
     "search_placeholder_hint": "E-mail zoeken... (druk /)",
     "mail": "E-mail",
@@ -377,6 +378,9 @@
     "moved_to_mailbox": "Verplaatst naar {mailbox}",
     "move_failed": "Verplaatsen mislukt",
     "move_error": "Kan e-mails niet verplaatsen naar de geselecteerde map",
+    "email_tagged": "E-mail gelabeld",
+    "emails_tagged": "{count} e-mails gelabeld",
+    "tag_failed": "Labelen mislukt",
     "identity_created": "Identiteit succesvol aangemaakt",
     "identity_updated": "Identiteit succesvol bijgewerkt",
     "identity_deleted": "Identiteit verwijderd",

locales/pt/common.json

@@ -91,6 +91,7 @@
     },
     "clear_search": "Limpar busca",
     "vacation_active": "Resposta automática ativa",
+    "tags": "Etiquetas",
     "compose_hint": "Compor (c)",
     "search_placeholder_hint": "Pesquisar e-mail... (pressione /)",
     "mail": "E-mail",
@@ -377,6 +378,9 @@
     "moved_to_mailbox": "Movido para {mailbox}",
     "move_failed": "Falha ao mover",
     "move_error": "Não foi possível mover os e-mails para a pasta selecionada",
+    "email_tagged": "E-mail etiquetado",
+    "emails_tagged": "{count} e-mails etiquetados",
+    "tag_failed": "Falha ao etiquetar",
     "identity_created": "Identidade criada com sucesso",
     "identity_updated": "Identidade atualizada com sucesso",
     "identity_deleted": "Identidade excluída",

stores/email-store.ts

@@ -29,6 +29,9 @@ interface EmailStore {
   threadEmailsCache: Map<string, Email[]>;
   isLoadingThread: string | null;
 
+  // Keyword/tag filter
+  selectedKeyword: string | null;
+
   // Advanced search state
   searchFilters: SearchFilters;
   isAdvancedSearchOpen: boolean;
@@ -43,6 +46,7 @@ interface EmailStore {
   setError: (error: string | null) => void;
   setSearchQuery: (query: string) => void;
   setQuota: (quota: { used: number; total: number } | null) => void;
+  selectKeyword: (keyword: string | null) => void;
   toggleEmailSelection: (emailId: string) => void;
   selectRangeEmails: (targetEmailId: string) => void;
   lastSelectedEmailId: string | null;
@@ -126,6 +130,9 @@ export const useEmailStore = create<EmailStore>((set, get) => ({
   threadEmailsCache: new Map(),
   isLoadingThread: null,
 
+  // Keyword/tag filter
+  selectedKeyword: null,
+
   // Advanced search state
   searchFilters: { ...DEFAULT_SEARCH_FILTERS },
   isAdvancedSearchOpen: false,
@@ -137,10 +144,18 @@ export const useEmailStore = create<EmailStore>((set, get) => ({
   setEmails: (emails) => set({ emails }),
   setMailboxes: (mailboxes) => set({ mailboxes }),
   selectEmail: (email) => set({ selectedEmail: email, lastSelectedEmailId: email?.id ?? get().lastSelectedEmailId }),
+  selectKeyword: (keyword) => set({
+    selectedKeyword: keyword,
+    selectedEmail: null,
+    selectedEmailIds: new Set(),
+    expandedThreadIds: new Set(),
+    threadEmailsCache: new Map(),
+  }),
   selectMailbox: (mailboxId) => set({
     selectedMailbox: mailboxId,
     selectedEmail: null,
     selectedEmailIds: new Set(),
+    selectedKeyword: null,
     expandedThreadIds: new Set(),
     threadEmailsCache: new Map(),
     isLoadingThread: null,
@@ -231,7 +246,11 @@ export const useEmailStore = create<EmailStore>((set, get) => ({
       // Get emails per page from settings
       const emailsPerPage = useSettingsStore.getState().emailsPerPage;
 
-      const result = await client.getEmails(jmapMailboxId, accountId, emailsPerPage, 0);
+      // Build keyword filter if a tag is selected
+      const { selectedKeyword } = get();
+      const keywordFilter = selectedKeyword ? `$label:${selectedKeyword}` : undefined;
+
+      const result = await client.getEmails(jmapMailboxId, accountId, emailsPerPage, 0, keywordFilter);
       set({
         emails: result.emails,
         hasMoreEmails: result.hasMore,
@@ -251,7 +270,7 @@ export const useEmailStore = create<EmailStore>((set, get) => ({
   },
 
   loadMoreEmails: async (client) => {
-    const { isLoadingMore, hasMoreEmails, emails, selectedMailbox, searchQuery } = get();
+    const { isLoadingMore, hasMoreEmails, emails, selectedMailbox, searchQuery, selectedKeyword } = get();
 
     // Don't load if already loading or no more emails
     if (isLoadingMore || !hasMoreEmails) return;
@@ -288,7 +307,7 @@ export const useEmailStore = create<EmailStore>((set, get) => ({
         // Use originalId for JMAP queries (shared mailboxes use namespaced IDs in the store)
         const jmapMailboxId = mailbox?.originalId || selectedMailbox;
 
-        result = await client.getEmails(jmapMailboxId, accountId, emailsPerPage, emails.length);
+        result = await client.getEmails(jmapMailboxId, accountId, emailsPerPage, emails.length, selectedKeyword ? `$label:${selectedKeyword}` : undefined);
       }
 
       set({