diff --git a/app/(main)/[locale]/page.tsx b/app/(main)/[locale]/page.tsx
index aa22ae36..1e1c601e 100644
--- a/app/(main)/[locale]/page.tsx
+++ b/app/(main)/[locale]/page.tsx
@@ -15,7 +15,7 @@ import { ThreadGroup, Email, isUnifiedMailboxId, UNIFIED_ROLE_BY_ID } from "@/li
 import { useAccountStore } from "@/stores/account-store";
 import type { UnifiedAccountClient } from "@/lib/unified-mailbox";
 import { KeyboardShortcutsModal } from "@/components/keyboard-shortcuts-modal";
-import { useEmailStore } from "@/stores/email-store";
+import { useEmailStore, buildUnifiedAccountClients } from "@/stores/email-store";
 import { toast } from "@/stores/toast-store";
 import { useAuthStore, redirectToLogin } from "@/stores/auth-store";
 import { useSettingsStore } from "@/stores/settings-store";
@@ -294,47 +294,22 @@ export default function Home() {
   useProMultiAccountMailboxes();
 
   const enableUnifiedMailbox = useSettingsStore((s) => s.enableUnifiedMailbox);
+  const includeGroupInUnified = useSettingsStore((s) => s.includeGroupInUnified);
   const accounts = useAccountStore((s) => s.accounts);
   const connectedAccountsSignature = useMemo(
     () => accounts.filter((a) => a.isConnected).map((a) => a.id).sort().join(","),
     [accounts],
   );
 
-  const buildUnifiedAccounts = useCallback((): UnifiedAccountClient[] => {
-    const connected = useAccountStore.getState().accounts.filter((a) => a.isConnected);
-    const clients = useAuthStore.getState().getAllConnectedClients();
-    const result: UnifiedAccountClient[] = [];
-    for (const account of connected) {
-      const accountClient = clients.get(account.id);
-      if (!accountClient) continue;
-      result.push({
-        accountId: account.id,
-        accountLabel: account.label || account.email,
-        client: accountClient,
-        mailboxes: [],
-      });
-    }
-    return result;
+  // Builds the populated UnifiedAccountClient[] used by the unified-view
+  // effects and one-shot actions in this page. Reads the includeGroup
+  // setting at call time so the latest toggle value is always honored.
+  const buildPopulatedUnifiedAccounts = useCallback(async (): Promise<UnifiedAccountClient[]> => {
+    return buildUnifiedAccountClients({
+      includeGroup: useSettingsStore.getState().includeGroupInUnified,
+    });
   }, []);
 
-  const populateUnifiedAccountMailboxes = useCallback(
-    async (list: UnifiedAccountClient[]): Promise<UnifiedAccountClient[]> => {
-      const populated = await Promise.all(
-        list.map(async (entry) => {
-          try {
-            const mailboxes = await entry.client.getMailboxes();
-            return { ...entry, mailboxes };
-          } catch (err) {
-            debug.error('Failed to load mailboxes for unified account', entry.accountId, err);
-            return entry;
-          }
-        }),
-      );
-      return populated;
-    },
-    [],
-  );
-
   const getMailtoProtocolAccounts = useCallback(() => {
     const connectedClients = useAuthStore.getState().getAllConnectedClients();
     return useAccountStore.getState().accounts.filter((account) =>
@@ -890,12 +865,12 @@ export default function Home() {
   useEffect(() => {
     if (!enableUnifiedMailbox && !isEmbedded) return;
     if (!isAuthenticated || !client) return;
-    const built = buildUnifiedAccounts();
-    if (built.length < 2) return;
-    populateUnifiedAccountMailboxes(built).then((populated) => {
-      refreshUnifiedCounts(populated);
+    buildPopulatedUnifiedAccounts().then((built) => {
+      const hasGroupEntry = built.some((b) => b.isShared);
+      if (built.length < 2 && !hasGroupEntry && !isEmbedded) return;
+      refreshUnifiedCounts(built);
     });
-  }, [enableUnifiedMailbox, isEmbedded, isAuthenticated, client, mailboxes, connectedAccountsSignature, buildUnifiedAccounts, populateUnifiedAccountMailboxes, refreshUnifiedCounts]);
+  }, [enableUnifiedMailbox, includeGroupInUnified, isEmbedded, isAuthenticated, client, mailboxes, connectedAccountsSignature, buildPopulatedUnifiedAccounts, refreshUnifiedCounts]);
 
   // System-notification click handler. The push SW navigates the user back
   // here with `?email=<id>` (specific email it built the toast from) or
@@ -1475,8 +1450,7 @@ export default function Home() {
         setTabletListVisible(true);
       }
 
-      const built = buildUnifiedAccounts();
-      const populated = await populateUnifiedAccountMailboxes(built);
+      const populated = await buildPopulatedUnifiedAccounts();
       await fetchUnifiedEmailsAction(populated, role);
       refreshUnifiedCounts(populated);
       return;
@@ -1821,8 +1795,7 @@ export default function Home() {
     if (isUnifiedView) {
       const role = useEmailStore.getState().unifiedRole;
       if (role) {
-        const built = buildUnifiedAccounts();
-        const populated = await populateUnifiedAccountMailboxes(built);
+        const populated = await buildPopulatedUnifiedAccounts();
         await fetchUnifiedEmailsAction(populated, role);
       }
       return;
diff --git a/components/layout/sidebar.tsx b/components/layout/sidebar.tsx
index a67ccab2..df38d387 100644
--- a/components/layout/sidebar.tsx
+++ b/components/layout/sidebar.tsx
@@ -1,6 +1,6 @@
 "use client";
 
-import { useState, useEffect, ReactNode } from "react";
+import { useState, useEffect, useMemo, ReactNode } from "react";
 import { useTranslations } from "next-intl";
 import { useRouter } from "@/i18n/navigation";
 import { PluginSlot } from "@/components/plugins/plugin-slot";
@@ -732,15 +732,20 @@ export function Sidebar({
   // pane.
   const hideAccountSwitcher = useSettingsStore(s => s.hideAccountSwitcher) || isEmbedded;
   const enableUnifiedMailbox = useSettingsStore(s => s.enableUnifiedMailbox);
+  const includeGroupInUnified = useSettingsStore(s => s.includeGroupInUnified);
   const colorfulSidebarIcons = useSettingsStore(s => s.colorfulSidebarIcons);
   const tagCounts = useEmailStore(s => s.tagCounts);
   const accounts = useAccountStore(s => s.accounts);
   const connectedAccounts = accounts.filter(a => a.isConnected);
+  const hasGroupInboxes = useMemo(() => mailboxes.some(m => m.isShared), [mailboxes]);
   // Pro shell treats the unified mailbox as a core part of the multi-account
-  // UI, so it ignores the user-facing `enableUnifiedMailbox` toggle. The
-  // 2+ account requirement still applies - with a single account the
-  // unified counts would just duplicate that account's inbox.
-  const showUnified = (multiAccountMode || enableUnifiedMailbox) && connectedAccounts.length > 1;
+  // UI, so it ignores the user-facing `enableUnifiedMailbox` toggle. With a
+  // single account we still surface unified when the user has opted into
+  // merging group/shared inboxes — otherwise the counts would just duplicate
+  // the one inbox.
+  const showUnified =
+    (multiAccountMode || enableUnifiedMailbox) &&
+    (connectedAccounts.length > 1 || (includeGroupInUnified && hasGroupInboxes));
   const { unifiedCounts } = useEmailStore();
   const t = useTranslations('sidebar');
 
diff --git a/components/settings/layout-settings.tsx b/components/settings/layout-settings.tsx
index a3ac41c6..b4d08c4f 100644
--- a/components/settings/layout-settings.tsx
+++ b/components/settings/layout-settings.tsx
@@ -1,11 +1,13 @@
 "use client";
 
+import { useMemo } from 'react';
 import { useTranslations } from 'next-intl';
 import { useSettingsStore, type ToolbarPosition, type MailLayout } from '@/stores/settings-store';
 import { SettingsSection, SettingItem, RadioGroup, ToggleSwitch } from './settings-section';
 import { cn } from '@/lib/utils';
 import { usePolicyStore } from '@/stores/policy-store';
 import { useAccountStore } from '@/stores/account-store';
+import { useEmailStore } from '@/stores/email-store';
 
 const MAIL_LAYOUT_PREVIEW_ROWS = [
   { sender: 'Alice', subject: 'Quarterly roadmap', preview: 'The draft is ready for review.', selected: false },
@@ -115,9 +117,11 @@ function MailLayoutPreview({
 export function LayoutSettings() {
   const t = useTranslations('settings.appearance');
   const tEmail = useTranslations('settings.email_behavior');
-  const { toolbarPosition, showToolbarLabels, hideAccountSwitcher, showRailAccountList, enableUnifiedMailbox, colorfulSidebarIcons, mailLayout, proInterface, updateSetting } = useSettingsStore();
+  const { toolbarPosition, showToolbarLabels, hideAccountSwitcher, showRailAccountList, enableUnifiedMailbox, includeGroupInUnified, colorfulSidebarIcons, mailLayout, proInterface, updateSetting } = useSettingsStore();
   const { isSettingLocked, isSettingHidden } = usePolicyStore();
   const accounts = useAccountStore(s => s.accounts);
+  const mailboxes = useEmailStore(s => s.mailboxes);
+  const hasGroupInboxes = useMemo(() => mailboxes.some(m => m.isShared), [mailboxes]);
 
   return (
     <SettingsSection title={t('title')} description={t('description')}>
@@ -177,10 +181,11 @@ export function LayoutSettings() {
         />
       </SettingItem>
 
-      {accounts.length > 1 && (
+      {(accounts.length > 1 || hasGroupInboxes) && !isSettingHidden('enableUnifiedMailbox') && (
         <SettingItem
           label={t('unified_mailbox.label')}
           description={t('unified_mailbox.description')}
+          locked={isSettingLocked('enableUnifiedMailbox')}
         >
           <ToggleSwitch
             checked={enableUnifiedMailbox}
@@ -189,6 +194,21 @@ export function LayoutSettings() {
         </SettingItem>
       )}
 
+      {enableUnifiedMailbox && hasGroupInboxes && !isSettingHidden('includeGroupInUnified') && (
+        <div className="ml-4 border-l-2 border-border pl-4 -mt-2">
+          <SettingItem
+            label={t('unified_mailbox.include_group.label')}
+            description={t('unified_mailbox.include_group.description')}
+            locked={isSettingLocked('includeGroupInUnified')}
+          >
+            <ToggleSwitch
+              checked={includeGroupInUnified}
+              onChange={(v) => updateSetting('includeGroupInUnified', v)}
+            />
+          </SettingItem>
+        </div>
+      )}
+
       <SettingItem label={t('pro_interface.label')} description={t('pro_interface.description')}>
         <ToggleSwitch
           checked={proInterface}
diff --git a/lib/unified-mailbox.ts b/lib/unified-mailbox.ts
index f1f38649..1b3a1f8e 100644
--- a/lib/unified-mailbox.ts
+++ b/lib/unified-mailbox.ts
@@ -6,6 +6,11 @@ export interface UnifiedAccountClient {
   accountLabel: string;
   client: IJMAPClient;
   mailboxes: Mailbox[];
+  // When true, this entry represents a group/shared account owned by
+  // `accountId` but accessed through someone else's `client`. JMAP requests
+  // must use the mailbox's `originalId` and explicitly target this accountId
+  // so the server routes to the owner's data.
+  isShared?: boolean;
 }
 
 export interface UnifiedFetchResult {
@@ -60,10 +65,11 @@ export async function fetchUnifiedEmails(
       const mailbox = findMailboxByRole(account.mailboxes, role);
       if (!mailbox) return null;
 
+      const { jmapMailboxId, jmapAccountId } = resolveJmapTarget(account, mailbox);
       try {
         const result = await account.client.getEmails(
-          mailbox.id,
-          undefined,
+          jmapMailboxId,
+          jmapAccountId,
           limit,
           position,
         );
@@ -131,7 +137,8 @@ export async function searchUnifiedEmails(
   position: number,
 ): Promise<UnifiedFetchResult> {
   return fanOutUnifiedQuery(accounts, role, async (account, mailbox) => {
-    return account.client.searchEmails(query, mailbox.id, undefined, limit, position);
+    const { jmapMailboxId, jmapAccountId } = resolveJmapTarget(account, mailbox);
+    return account.client.searchEmails(query, jmapMailboxId, jmapAccountId, limit, position);
   });
 }
 
@@ -149,10 +156,31 @@ export async function advancedSearchUnifiedEmails(
   position: number,
 ): Promise<UnifiedFetchResult> {
   return fanOutUnifiedQuery(accounts, role, async (account, mailbox) => {
-    return account.client.advancedSearchEmails(filterFor(mailbox.id), undefined, limit, position);
+    const { jmapMailboxId, jmapAccountId } = resolveJmapTarget(account, mailbox);
+    return account.client.advancedSearchEmails(filterFor(jmapMailboxId), jmapAccountId, limit, position);
   });
 }
 
+/**
+ * Resolves the JMAP-side mailbox id and accountId for a mailbox living inside
+ * a UnifiedAccountClient. For personal-account entries we use the JMAP id as
+ * returned by the primary client; for shared-owner entries the mailbox id is
+ * namespaced (`${ownerId}:${origId}`) so we must use `originalId` and pass the
+ * owner's accountId through the request.
+ */
+function resolveJmapTarget(
+  account: UnifiedAccountClient,
+  mailbox: Mailbox,
+): { jmapMailboxId: string; jmapAccountId: string | undefined } {
+  if (account.isShared) {
+    return {
+      jmapMailboxId: mailbox.originalId ?? mailbox.id,
+      jmapAccountId: account.accountId,
+    };
+  }
+  return { jmapMailboxId: mailbox.id, jmapAccountId: undefined };
+}
+
 async function fanOutUnifiedQuery(
   accounts: UnifiedAccountClient[],
   role: UnifiedMailboxRole,
diff --git a/locales/cs/common.json b/locales/cs/common.json
index 4c08babd..ba4801a0 100644
--- a/locales/cs/common.json
+++ b/locales/cs/common.json
@@ -844,7 +844,11 @@
       },
       "unified_mailbox": {
         "label": "Sjednocená schránka",
-        "description": "Zobrazovat sloučené složky (Doručené, Odeslané atd.) ze všech připojených účtů"
+        "description": "Zobrazovat sloučené složky (Doručené, Odeslané atd.) ze všech připojených účtů",
+        "include_group": {
+          "label": "Zahrnout skupinové schránky",
+          "description": "Zahrnout do sjednoceného zobrazení také sdílené/skupinové schránky."
+        }
       },
       "colorful_sidebar_icons": {
         "label": "Barevné ikony postranního panelu",
diff --git a/locales/da/common.json b/locales/da/common.json
index eb488cf3..12e51df1 100644
--- a/locales/da/common.json
+++ b/locales/da/common.json
@@ -847,7 +847,11 @@
       },
       "unified_mailbox": {
         "label": "Samlet postkasse",
-        "description": "Vis samlede mapper (Indbakke, Sendt osv.) på tværs af alle tilknyttede konti"
+        "description": "Vis samlede mapper (Indbakke, Sendt osv.) på tværs af alle tilknyttede konti",
+        "include_group": {
+          "label": "Inkluder gruppepostkasser",
+          "description": "Inkluder også delte/gruppepostkasser i den samlede visning."
+        }
       },
       "colorful_sidebar_icons": {
         "label": "Farverige sidepane-ikoner",
diff --git a/locales/de/common.json b/locales/de/common.json
index 35f6ff03..e834e9a7 100644
--- a/locales/de/common.json
+++ b/locales/de/common.json
@@ -844,7 +844,11 @@
       },
       "unified_mailbox": {
         "label": "Gemeinsames Postfach",
-        "description": "Kombinierte Ordner (Posteingang, Gesendet usw.) für alle verbundenen Konten anzeigen"
+        "description": "Kombinierte Ordner (Posteingang, Gesendet usw.) für alle verbundenen Konten anzeigen",
+        "include_group": {
+          "label": "Gruppenpostfächer einbeziehen",
+          "description": "Gemeinsam genutzte/Gruppenpostfächer ebenfalls in die vereinheitlichte Ansicht aufnehmen."
+        }
       },
       "colorful_sidebar_icons": {
         "label": "Farbige Seitenleistensymbole",
diff --git a/locales/en/common.json b/locales/en/common.json
index 43545e7d..d916c100 100644
--- a/locales/en/common.json
+++ b/locales/en/common.json
@@ -847,7 +847,11 @@
       },
       "unified_mailbox": {
         "label": "Unified Mailbox",
-        "description": "Show combined folders (Inbox, Sent, etc.) across all connected accounts"
+        "description": "Show combined folders (Inbox, Sent, etc.) across all connected accounts",
+        "include_group": {
+          "label": "Include group inboxes",
+          "description": "Also merge shared/group inboxes into the unified view."
+        }
       },
       "colorful_sidebar_icons": {
         "label": "Colorful Sidebar Icons",
diff --git a/locales/es/common.json b/locales/es/common.json
index 9db24167..950a5e37 100644
--- a/locales/es/common.json
+++ b/locales/es/common.json
@@ -844,7 +844,11 @@
       },
       "unified_mailbox": {
         "label": "Buzón unificado",
-        "description": "Mostrar carpetas combinadas (Entrada, Enviados, etc.) de todas las cuentas conectadas"
+        "description": "Mostrar carpetas combinadas (Entrada, Enviados, etc.) de todas las cuentas conectadas",
+        "include_group": {
+          "label": "Incluir buzones de grupo",
+          "description": "Incluir también los buzones compartidos o de grupo en la vista unificada."
+        }
       },
       "colorful_sidebar_icons": {
         "label": "Iconos de barra lateral a color",
diff --git a/locales/fr/common.json b/locales/fr/common.json
index 5c9f2d81..f3c7067d 100644
--- a/locales/fr/common.json
+++ b/locales/fr/common.json
@@ -844,7 +844,11 @@
       },
       "unified_mailbox": {
         "label": "Boîte aux lettres unifiée",
-        "description": "Afficher les dossiers combinés (Réception, Envoyés, etc.) de tous les comptes connectés"
+        "description": "Afficher les dossiers combinés (Réception, Envoyés, etc.) de tous les comptes connectés",
+        "include_group": {
+          "label": "Inclure les boîtes de groupe",
+          "description": "Inclure également les boîtes partagées ou de groupe dans la vue unifiée."
+        }
       },
       "colorful_sidebar_icons": {
         "label": "Icônes colorées dans la barre latérale",
diff --git a/locales/it/common.json b/locales/it/common.json
index 48b08ce6..7723fe38 100644
--- a/locales/it/common.json
+++ b/locales/it/common.json
@@ -844,7 +844,11 @@
       },
       "unified_mailbox": {
         "label": "Casella di posta unificata",
-        "description": "Mostra le cartelle combinate (Posta in arrivo, Inviati, ecc.) di tutti gli account collegati"
+        "description": "Mostra le cartelle combinate (Posta in arrivo, Inviati, ecc.) di tutti gli account collegati",
+        "include_group": {
+          "label": "Includi le caselle di gruppo",
+          "description": "Includi anche le caselle condivise o di gruppo nella vista unificata."
+        }
       },
       "colorful_sidebar_icons": {
         "label": "Icone colorate nella barra laterale",
diff --git a/locales/ja/common.json b/locales/ja/common.json
index afbb41a9..8f37e703 100644
--- a/locales/ja/common.json
+++ b/locales/ja/common.json
@@ -844,7 +844,11 @@
       },
       "unified_mailbox": {
         "label": "統合メールボックス",
-        "description": "接続されたすべてのアカウントの統合フォルダ（受信トレイ、送信済みなど）を表示"
+        "description": "接続されたすべてのアカウントの統合フォルダ（受信トレイ、送信済みなど）を表示",
+        "include_group": {
+          "label": "グループ受信トレイを含める",
+          "description": "共有/グループ受信トレイも統合ビューに含めます。"
+        }
       },
       "colorful_sidebar_icons": {
         "label": "カラフルなサイドバーアイコン",
diff --git a/locales/ko/common.json b/locales/ko/common.json
index 000eed02..722fbf06 100644
--- a/locales/ko/common.json
+++ b/locales/ko/common.json
@@ -844,7 +844,11 @@
       },
       "unified_mailbox": {
         "label": "통합 메일함",
-        "description": "연결된 모든 계정의 통합 폴더(받은편지함, 보낸편지함 등)를 표시합니다"
+        "description": "연결된 모든 계정의 통합 폴더(받은편지함, 보낸편지함 등)를 표시합니다",
+        "include_group": {
+          "label": "그룹 받은편지함 포함",
+          "description": "공유/그룹 받은편지함도 통합 보기에 포함합니다."
+        }
       },
       "colorful_sidebar_icons": {
         "label": "컬러풀한 사이드바 아이콘",
diff --git a/locales/lv/common.json b/locales/lv/common.json
index 87b73bcd..7c4311a2 100644
--- a/locales/lv/common.json
+++ b/locales/lv/common.json
@@ -844,7 +844,11 @@
       },
       "unified_mailbox": {
         "label": "Apvienotā pastkaste",
-        "description": "Rādīt apvienotās mapes (Iesūtne, Nosūtītie u.c.) no visiem pievienotajiem kontiem"
+        "description": "Rādīt apvienotās mapes (Iesūtne, Nosūtītie u.c.) no visiem pievienotajiem kontiem",
+        "include_group": {
+          "label": "Iekļaut grupas pastkastes",
+          "description": "Iekļaut apvienotajā skatā arī koplietotās/grupas pastkastes."
+        }
       },
       "colorful_sidebar_icons": {
         "label": "Krāsainas sānjoslas ikonas",
diff --git a/locales/nl/common.json b/locales/nl/common.json
index 94feb1c1..ea6ad7db 100644
--- a/locales/nl/common.json
+++ b/locales/nl/common.json
@@ -844,7 +844,11 @@
       },
       "unified_mailbox": {
         "label": "Gecombineerd postvak",
-        "description": "Gecombineerde mappen (Postvak IN, Verzonden, enz.) van alle verbonden accounts weergeven"
+        "description": "Gecombineerde mappen (Postvak IN, Verzonden, enz.) van alle verbonden accounts weergeven",
+        "include_group": {
+          "label": "Groepspostvakken meenemen",
+          "description": "Gedeelde/groepspostvakken ook in de gecombineerde weergave opnemen."
+        }
       },
       "colorful_sidebar_icons": {
         "label": "Gekleurde zijbalkpictogrammen",
diff --git a/locales/pl/common.json b/locales/pl/common.json
index b7268818..2ff0dc34 100644
--- a/locales/pl/common.json
+++ b/locales/pl/common.json
@@ -844,7 +844,11 @@
       },
       "unified_mailbox": {
         "label": "Wspólna skrzynka",
-        "description": "Wyświetlaj połączone foldery (Odebrane, Wysłane itp.) ze wszystkich połączonych kont"
+        "description": "Wyświetlaj połączone foldery (Odebrane, Wysłane itp.) ze wszystkich połączonych kont",
+        "include_group": {
+          "label": "Uwzględnij skrzynki grupowe",
+          "description": "Dodaj również udostępnione/grupowe skrzynki do widoku wspólnego."
+        }
       },
       "colorful_sidebar_icons": {
         "label": "Kolorowe ikony paska bocznego",
diff --git a/locales/pt/common.json b/locales/pt/common.json
index 2607d856..489605fe 100644
--- a/locales/pt/common.json
+++ b/locales/pt/common.json
@@ -844,7 +844,11 @@
       },
       "unified_mailbox": {
         "label": "Caixa de correio unificada",
-        "description": "Mostrar pastas combinadas (Entrada, Enviados, etc.) de todas as contas conectadas"
+        "description": "Mostrar pastas combinadas (Entrada, Enviados, etc.) de todas as contas conectadas",
+        "include_group": {
+          "label": "Incluir caixas de grupo",
+          "description": "Incluir também as caixas partilhadas ou de grupo na vista unificada."
+        }
       },
       "colorful_sidebar_icons": {
         "label": "Ícones coloridos na barra lateral",
diff --git a/locales/ru/common.json b/locales/ru/common.json
index fb02ab99..da8e624b 100644
--- a/locales/ru/common.json
+++ b/locales/ru/common.json
@@ -844,7 +844,11 @@
       },
       "unified_mailbox": {
         "label": "Общий почтовый ящик",
-        "description": "Показывать объединённые папки (Входящие, Отправленные и др.) для всех подключённых аккаунтов"
+        "description": "Показывать объединённые папки (Входящие, Отправленные и др.) для всех подключённых аккаунтов",
+        "include_group": {
+          "label": "Включать групповые ящики",
+          "description": "Также объединять общие/групповые ящики в едином представлении."
+        }
       },
       "colorful_sidebar_icons": {
         "label": "Цветные значки боковой панели",
diff --git a/locales/tr/common.json b/locales/tr/common.json
index 1b20c920..c9e6648a 100644
--- a/locales/tr/common.json
+++ b/locales/tr/common.json
@@ -844,7 +844,11 @@
       },
       "unified_mailbox": {
         "label": "Birleşik Posta Kutusu",
-        "description": "Bağlı tüm hesaplardaki birleşik klasörleri (Gelen Kutusu, Gönderilenler vb.) göster"
+        "description": "Bağlı tüm hesaplardaki birleşik klasörleri (Gelen Kutusu, Gönderilenler vb.) göster",
+        "include_group": {
+          "label": "Grup gelen kutularını dahil et",
+          "description": "Paylaşılan/grup gelen kutularını da birleşik görünüme dahil et."
+        }
       },
       "colorful_sidebar_icons": {
         "label": "Renkli Kenar Çubuğu Simgeleri",
diff --git a/locales/uk/common.json b/locales/uk/common.json
index 22f7eeab..54bc2ec1 100644
--- a/locales/uk/common.json
+++ b/locales/uk/common.json
@@ -844,7 +844,11 @@
       },
       "unified_mailbox": {
         "label": "Спільна поштова скринька",
-        "description": "Показувати об'єднані папки (Вхідні, Надіслані тощо) для всіх підключених облікових записів"
+        "description": "Показувати об'єднані папки (Вхідні, Надіслані тощо) для всіх підключених облікових записів",
+        "include_group": {
+          "label": "Включати групові скриньки",
+          "description": "Також об'єднувати спільні/групові скриньки у спільному перегляді."
+        }
       },
       "colorful_sidebar_icons": {
         "label": "Кольорові значки бічної панелі",
diff --git a/locales/zh/common.json b/locales/zh/common.json
index eeea6593..2be4f21e 100644
--- a/locales/zh/common.json
+++ b/locales/zh/common.json
@@ -844,7 +844,11 @@
       },
       "unified_mailbox": {
         "label": "统一邮箱",
-        "description": "显示所有已连接账户的合并文件夹（收件箱、已发送等）"
+        "description": "显示所有已连接账户的合并文件夹（收件箱、已发送等）",
+        "include_group": {
+          "label": "包含群组收件箱",
+          "description": "在统一视图中也合并共享/群组收件箱。"
+        }
       },
       "colorful_sidebar_icons": {
         "label": "彩色侧边栏图标",
diff --git a/stores/email-store.ts b/stores/email-store.ts
index 9798792e..44ee2d00 100644
--- a/stores/email-store.ts
+++ b/stores/email-store.ts
@@ -251,8 +251,16 @@ function resolveActionMailboxes(): Mailbox[] {
  * fresh mailbox list so the helpers can resolve the role mailbox per account.
  * Accounts whose mailbox fetch fails are skipped - the unified result will
  * surface that in its per-account error map.
+ *
+ * When `includeGroup` is true, also emits one synthetic entry per shared
+ * owner account reachable through each logged-in client. The shared entries
+ * are flagged with `isShared: true` so `lib/unified-mailbox.ts` routes JMAP
+ * requests via `originalId` + owner accountId.
  */
-async function buildUnifiedAccountClients(): Promise<UnifiedAccountClient[]> {
+export async function buildUnifiedAccountClients(
+  opts: { includeGroup?: boolean } = {},
+): Promise<UnifiedAccountClient[]> {
+  const { includeGroup = false } = opts;
   const authAccounts = useAccountStore.getState().accounts.filter((a) => a.isConnected);
   const allClients = useAuthStore.getState().getAllConnectedClients();
   const built: UnifiedAccountClient[] = [];
@@ -260,8 +268,31 @@ async function buildUnifiedAccountClients(): Promise<UnifiedAccountClient[]> {
     const c = allClients.get(a.id);
     if (!c) continue;
     try {
-      const mailboxes = await c.getMailboxes();
-      built.push({ accountId: a.id, accountLabel: a.label || a.email, client: c, mailboxes });
+      const mailboxes = includeGroup ? await c.getAllMailboxes() : await c.getMailboxes();
+      const ownMailboxes = includeGroup
+        ? mailboxes.filter((m) => !m.isShared)
+        : mailboxes;
+      built.push({ accountId: a.id, accountLabel: a.label || a.email, client: c, mailboxes: ownMailboxes, isShared: false });
+
+      if (includeGroup) {
+        const sharedByOwner = new Map<string, Mailbox[]>();
+        for (const m of mailboxes) {
+          if (!m.isShared || !m.accountId || m.accountId === a.id) continue;
+          const list = sharedByOwner.get(m.accountId) ?? [];
+          list.push(m);
+          sharedByOwner.set(m.accountId, list);
+        }
+        for (const [ownerId, ownerMailboxes] of sharedByOwner) {
+          const label = ownerMailboxes.find((m) => m.accountName)?.accountName || ownerId;
+          built.push({
+            accountId: ownerId,
+            accountLabel: label,
+            client: c,
+            mailboxes: ownerMailboxes,
+            isShared: true,
+          });
+        }
+      }
     } catch {
       /* skip account on mailbox fetch failure */
     }
@@ -583,8 +614,9 @@ export const useEmailStore = create<EmailStore>((set, get) => ({
       set({ isLoadingMore: true, error: null });
       try {
         const emailsPerPage = useSettingsStore.getState().emailsPerPage;
+        const includeGroup = useSettingsStore.getState().includeGroupInUnified;
         const position = emails.length;
-        const built = await buildUnifiedAccountClients();
+        const built = await buildUnifiedAccountClients({ includeGroup });
         const { searchFilters } = get();
         const hasFilters = !isFilterEmpty(searchFilters);
         const result = hasFilters
@@ -1261,7 +1293,8 @@ export const useEmailStore = create<EmailStore>((set, get) => ({
       const emailsPerPage = useSettingsStore.getState().emailsPerPage;
 
       if (isUnifiedView && unifiedRole) {
-        const built = await buildUnifiedAccountClients();
+        const includeGroup = useSettingsStore.getState().includeGroupInUnified;
+        const built = await buildUnifiedAccountClients({ includeGroup });
         const result = await searchUnifiedEmails(built, unifiedRole, query, emailsPerPage, 0);
         const externals = await emailHooks.onProvideSearchResults.transform([] as ExternalSearchResult[], { query, filters: get().searchFilters });
         set({
@@ -1327,7 +1360,8 @@ export const useEmailStore = create<EmailStore>((set, get) => ({
       const emailsPerPage = useSettingsStore.getState().emailsPerPage;
 
       if (isUnifiedView && unifiedRole) {
-        const built = await buildUnifiedAccountClients();
+        const includeGroup = useSettingsStore.getState().includeGroupInUnified;
+        const built = await buildUnifiedAccountClients({ includeGroup });
         const result = await advancedSearchUnifiedEmails(
           built,
           unifiedRole,
diff --git a/stores/settings-store.ts b/stores/settings-store.ts
index fd8dcfe1..a93ab891 100644
--- a/stores/settings-store.ts
+++ b/stores/settings-store.ts
@@ -202,6 +202,7 @@ interface SettingsState {
 
   // Unified Mailbox
   enableUnifiedMailbox: boolean;
+  includeGroupInUnified: boolean;
 
   // Email Display
   disableThreading: boolean; // Show emails as individual messages instead of grouped by conversation
@@ -375,6 +376,7 @@ const DEFAULT_SETTINGS = {
 
   // Unified Mailbox
   enableUnifiedMailbox: false,
+  includeGroupInUnified: false,
 
   // Email Display
   disableThreading: false,
@@ -543,6 +545,7 @@ export const useSettingsStore = create<SettingsState>()(
           // proInterface is intentionally omitted - it's a per-device choice
           // (see DEVICE_LOCAL_SETTING_KEYS) and must not be synced.
           enableUnifiedMailbox: state.enableUnifiedMailbox,
+          includeGroupInUnified: state.includeGroupInUnified,
           senderFavicons: state.senderFavicons,
           showAvatarsInJunk: state.showAvatarsInJunk,
           colorfulSidebarIcons: state.colorfulSidebarIcons,