diff --git a/packages/twenty-client-sdk/src/metadata/generated/schema.graphql b/packages/twenty-client-sdk/src/metadata/generated/schema.graphql
index 09f35091ad..ee4b7d8a01 100644
--- a/packages/twenty-client-sdk/src/metadata/generated/schema.graphql
+++ b/packages/twenty-client-sdk/src/metadata/generated/schema.graphql
@@ -2987,6 +2987,7 @@ type Query {
   ): IndexConnection!
   findManyAgents: [Agent!]!
   findOneAgent(input: AgentIdInput!): Agent!
+  myConnectedAccounts: [ConnectedAccountPublicDTO!]!
   getRoles: [Role!]!
   getToolIndex: [ToolIndexEntry!]!
   getToolInputSchema(toolName: String!): JSON
@@ -3007,7 +3008,6 @@ type Query {
   getViewGroup(id: String!): ViewGroup
   myMessageFolders(messageChannelId: UUID): [MessageFolder!]!
   myMessageChannels(connectedAccountId: UUID): [MessageChannel!]!
-  myConnectedAccounts: [ConnectedAccountPublicDTO!]!
   myCalendarChannels(connectedAccountId: UUID): [CalendarChannel!]!
   minimalMetadata: MinimalMetadata!
   findWorkspaceAiStats: WorkspaceAiStats!
@@ -3226,6 +3226,7 @@ type Mutation {
   createOneAgent(input: CreateAgentInput!): Agent!
   updateOneAgent(input: UpdateAgentInput!): Agent!
   deleteOneAgent(input: AgentIdInput!): Agent!
+  deleteConnectedAccount(id: UUID!): ConnectedAccountPublicDTO!
   updateWorkspaceMemberRole(workspaceMemberId: UUID!, roleId: UUID!): WorkspaceMember!
   createOneRole(createRoleInput: CreateRoleInput!): Role!
   updateOneRole(updateRoleInput: UpdateRoleInput!): Role!
@@ -3253,7 +3254,6 @@ type Mutation {
   updateMessageChannel(input: UpdateMessageChannelInput!): MessageChannel!
   createEmailGroupChannel(input: CreateEmailGroupChannelInput!): CreateEmailGroupChannelOutput!
   deleteEmailGroupChannel(id: UUID!): MessageChannel!
-  deleteConnectedAccount(id: UUID!): ConnectedAccountPublicDTO!
   updateCalendarChannel(input: UpdateCalendarChannelInput!): CalendarChannel!
   createChatThread: AgentChatThread!
   sendChatMessage(threadId: UUID!, text: String!, messageId: UUID!, browsingContext: JSON, modelId: String, fileAttachments: [FileAttachmentInput!]): SendChatMessageResult!
diff --git a/packages/twenty-client-sdk/src/metadata/generated/schema.ts b/packages/twenty-client-sdk/src/metadata/generated/schema.ts
index e2bda1803c..dfb6062d4e 100644
--- a/packages/twenty-client-sdk/src/metadata/generated/schema.ts
+++ b/packages/twenty-client-sdk/src/metadata/generated/schema.ts
@@ -2593,6 +2593,7 @@ export interface Query {
     indexMetadatas: IndexConnection
     findManyAgents: Agent[]
     findOneAgent: Agent
+    myConnectedAccounts: ConnectedAccountPublicDTO[]
     getRoles: Role[]
     getToolIndex: ToolIndexEntry[]
     getToolInputSchema?: Scalars['JSON']
@@ -2604,7 +2605,6 @@ export interface Query {
     getViewGroup?: ViewGroup
     myMessageFolders: MessageFolder[]
     myMessageChannels: MessageChannel[]
-    myConnectedAccounts: ConnectedAccountPublicDTO[]
     myCalendarChannels: CalendarChannel[]
     minimalMetadata: MinimalMetadata
     findWorkspaceAiStats: WorkspaceAiStats
@@ -2756,6 +2756,7 @@ export interface Mutation {
     createOneAgent: Agent
     updateOneAgent: Agent
     deleteOneAgent: Agent
+    deleteConnectedAccount: ConnectedAccountPublicDTO
     updateWorkspaceMemberRole: WorkspaceMember
     createOneRole: Role
     updateOneRole: Role
@@ -2783,7 +2784,6 @@ export interface Mutation {
     updateMessageChannel: MessageChannel
     createEmailGroupChannel: CreateEmailGroupChannelOutput
     deleteEmailGroupChannel: MessageChannel
-    deleteConnectedAccount: ConnectedAccountPublicDTO
     updateCalendarChannel: CalendarChannel
     createChatThread: AgentChatThread
     sendChatMessage: SendChatMessageResult
@@ -5626,6 +5626,7 @@ export interface QueryGenqlSelection{
     filter: IndexFilter} })
     findManyAgents?: AgentGenqlSelection
     findOneAgent?: (AgentGenqlSelection & { __args: {input: AgentIdInput} })
+    myConnectedAccounts?: ConnectedAccountPublicDTOGenqlSelection
     getRoles?: RoleGenqlSelection
     getToolIndex?: ToolIndexEntryGenqlSelection
     getToolInputSchema?: { __args: {toolName: Scalars['String']} }
@@ -5643,7 +5644,6 @@ export interface QueryGenqlSelection{
     getViewGroup?: (ViewGroupGenqlSelection & { __args: {id: Scalars['String']} })
     myMessageFolders?: (MessageFolderGenqlSelection & { __args?: {messageChannelId?: (Scalars['UUID'] | null)} })
     myMessageChannels?: (MessageChannelGenqlSelection & { __args?: {connectedAccountId?: (Scalars['UUID'] | null)} })
-    myConnectedAccounts?: ConnectedAccountPublicDTOGenqlSelection
     myCalendarChannels?: (CalendarChannelGenqlSelection & { __args?: {connectedAccountId?: (Scalars['UUID'] | null)} })
     minimalMetadata?: MinimalMetadataGenqlSelection
     findWorkspaceAiStats?: WorkspaceAiStatsGenqlSelection
@@ -5816,6 +5816,7 @@ export interface MutationGenqlSelection{
     createOneAgent?: (AgentGenqlSelection & { __args: {input: CreateAgentInput} })
     updateOneAgent?: (AgentGenqlSelection & { __args: {input: UpdateAgentInput} })
     deleteOneAgent?: (AgentGenqlSelection & { __args: {input: AgentIdInput} })
+    deleteConnectedAccount?: (ConnectedAccountPublicDTOGenqlSelection & { __args: {id: Scalars['UUID']} })
     updateWorkspaceMemberRole?: (WorkspaceMemberGenqlSelection & { __args: {workspaceMemberId: Scalars['UUID'], roleId: Scalars['UUID']} })
     createOneRole?: (RoleGenqlSelection & { __args: {createRoleInput: CreateRoleInput} })
     updateOneRole?: (RoleGenqlSelection & { __args: {updateRoleInput: UpdateRoleInput} })
@@ -5843,7 +5844,6 @@ export interface MutationGenqlSelection{
     updateMessageChannel?: (MessageChannelGenqlSelection & { __args: {input: UpdateMessageChannelInput} })
     createEmailGroupChannel?: (CreateEmailGroupChannelOutputGenqlSelection & { __args: {input: CreateEmailGroupChannelInput} })
     deleteEmailGroupChannel?: (MessageChannelGenqlSelection & { __args: {id: Scalars['UUID']} })
-    deleteConnectedAccount?: (ConnectedAccountPublicDTOGenqlSelection & { __args: {id: Scalars['UUID']} })
     updateCalendarChannel?: (CalendarChannelGenqlSelection & { __args: {input: UpdateCalendarChannelInput} })
     createChatThread?: AgentChatThreadGenqlSelection
     sendChatMessage?: (SendChatMessageResultGenqlSelection & { __args: {threadId: Scalars['UUID'], text: Scalars['String'], messageId: Scalars['UUID'], browsingContext?: (Scalars['JSON'] | null), modelId?: (Scalars['String'] | null), fileAttachments?: (FileAttachmentInput[] | null)} })
diff --git a/packages/twenty-client-sdk/src/metadata/generated/types.ts b/packages/twenty-client-sdk/src/metadata/generated/types.ts
index b1330e150b..c676ed29bf 100644
--- a/packages/twenty-client-sdk/src/metadata/generated/types.ts
+++ b/packages/twenty-client-sdk/src/metadata/generated/types.ts
@@ -6104,6 +6104,9 @@ export default {
                     ]
                 }
             ],
+            "myConnectedAccounts": [
+                270
+            ],
             "getRoles": [
                 29
             ],
@@ -6186,9 +6189,6 @@ export default {
                     ]
                 }
             ],
-            "myConnectedAccounts": [
-                270
-            ],
             "myCalendarChannels": [
                 303,
                 {
@@ -7577,6 +7577,15 @@ export default {
                     ]
                 }
             ],
+            "deleteConnectedAccount": [
+                270,
+                {
+                    "id": [
+                        3,
+                        "UUID!"
+                    ]
+                }
+            ],
             "updateWorkspaceMemberRole": [
                 20,
                 {
@@ -7828,15 +7837,6 @@ export default {
                     ]
                 }
             ],
-            "deleteConnectedAccount": [
-                270,
-                {
-                    "id": [
-                        3,
-                        "UUID!"
-                    ]
-                }
-            ],
             "updateCalendarChannel": [
                 303,
                 {
diff --git a/packages/twenty-server/src/engine/core-modules/tool/tool.module.ts b/packages/twenty-server/src/engine/core-modules/tool/tool.module.ts
index 333ae79821..6c458885d4 100644
--- a/packages/twenty-server/src/engine/core-modules/tool/tool.module.ts
+++ b/packages/twenty-server/src/engine/core-modules/tool/tool.module.ts
@@ -15,7 +15,7 @@ import { HttpTool } from 'src/engine/core-modules/tool/tools/http-tool/http-tool
 import { NavigateAppTool } from 'src/engine/core-modules/tool/tools/navigate-tool/navigate-app-tool';
 import { SearchHelpCenterTool } from 'src/engine/core-modules/tool/tools/search-help-center-tool/search-help-center-tool';
 import { WorkspaceManyOrAllFlatEntityMapsCacheModule } from 'src/engine/metadata-modules/flat-entity/services/workspace-many-or-all-flat-entity-maps-cache.module';
-import { ConnectedAccountEntity } from 'src/engine/metadata-modules/connected-account/entities/connected-account.entity';
+import { ConnectedAccountMetadataModule } from 'src/engine/metadata-modules/connected-account/connected-account-metadata.module';
 import { NavigationMenuItemModule } from 'src/engine/metadata-modules/navigation-menu-item/navigation-menu-item.module';
 import { ObjectMetadataModule } from 'src/engine/metadata-modules/object-metadata/object-metadata.module';
 import { ViewModule } from 'src/engine/metadata-modules/view/view.module';
@@ -26,7 +26,8 @@ import { provideWorkspaceScopedRepository } from 'src/engine/twenty-orm/workspac
   imports: [
     MessagingImportManagerModule,
     MessagingSendManagerModule,
-    TypeOrmModule.forFeature([FileEntity, ConnectedAccountEntity]),
+    TypeOrmModule.forFeature([FileEntity]),
+    ConnectedAccountMetadataModule,
     ApplicationModule,
     FeatureFlagModule,
     FileModule,
diff --git a/packages/twenty-server/src/engine/core-modules/tool/tools/email-tool/__tests__/email-composer.service.spec.ts b/packages/twenty-server/src/engine/core-modules/tool/tools/email-tool/__tests__/email-composer.service.spec.ts
new file mode 100644
index 0000000000..cc2e6c5146
--- /dev/null
+++ b/packages/twenty-server/src/engine/core-modules/tool/tools/email-tool/__tests__/email-composer.service.spec.ts
@@ -0,0 +1,287 @@
+import { randomUUID } from 'node:crypto';
+
+import { Test, type TestingModule } from '@nestjs/testing';
+
+import { ConnectedAccountProvider, FileFolder } from 'twenty-shared/types';
+import { isDefined } from 'twenty-shared/utils';
+
+import { EmailComposerService } from 'src/engine/core-modules/tool/tools/email-tool/email-composer.service';
+import { type ComposeEmailParams } from 'src/engine/core-modules/tool/tools/email-tool/types/compose-email-params.type';
+import { type ToolExecutionContext } from 'src/engine/core-modules/tool/types/tool-execution-context.type';
+import { FileEntity } from 'src/engine/core-modules/file/entities/file.entity';
+import { FileService } from 'src/engine/core-modules/file/services/file.service';
+import { ConnectedAccountMetadataService } from 'src/engine/metadata-modules/connected-account/connected-account-metadata.service';
+import { ConnectedAccountEntity } from 'src/engine/metadata-modules/connected-account/entities/connected-account.entity';
+import { GlobalWorkspaceOrmManager } from 'src/engine/twenty-orm/global-workspace-datasource/global-workspace-orm.manager';
+import { getWorkspaceScopedRepositoryToken } from 'src/engine/twenty-orm/workspace-scoped-repository/get-workspace-scoped-repository-token.util';
+
+const WORKSPACE_ID = randomUUID();
+const ALICE_USER_WORKSPACE_ID = randomUUID();
+const BOB_USER_WORKSPACE_ID = randomUUID();
+
+const ALICE_ACCOUNT_ID = randomUUID();
+const BOB_ACCOUNT_ID = randomUUID();
+const SHARED_ACCOUNT_ID = randomUUID();
+
+// In-memory connected accounts that mimic the rows TypeORM would return.
+type FakeAccount = Partial<ConnectedAccountEntity> & { id: string };
+
+const aliceUserPrivateAccount: FakeAccount = {
+  id: ALICE_ACCOUNT_ID,
+  workspaceId: WORKSPACE_ID,
+  userWorkspaceId: ALICE_USER_WORKSPACE_ID,
+  visibility: 'user',
+  handle: 'alice@example.com',
+  provider: ConnectedAccountProvider.GOOGLE,
+  connectionParameters: null,
+  messageChannels: [{ id: 'mc-alice', handle: 'alice@example.com' }] as never,
+};
+
+const bobUserPrivateAccount: FakeAccount = {
+  id: BOB_ACCOUNT_ID,
+  workspaceId: WORKSPACE_ID,
+  userWorkspaceId: BOB_USER_WORKSPACE_ID,
+  visibility: 'user',
+  handle: 'bob@example.com',
+  provider: ConnectedAccountProvider.GOOGLE,
+  connectionParameters: null,
+  messageChannels: [{ id: 'mc-bob', handle: 'bob@example.com' }] as never,
+};
+
+// Workspace-visibility account (owned by Alice but shared with the workspace).
+const sharedWorkspaceAccount: FakeAccount = {
+  id: SHARED_ACCOUNT_ID,
+  workspaceId: WORKSPACE_ID,
+  userWorkspaceId: ALICE_USER_WORKSPACE_ID,
+  visibility: 'workspace',
+  handle: 'team@example.com',
+  provider: ConnectedAccountProvider.GOOGLE,
+  connectionParameters: null,
+  messageChannels: [{ id: 'mc-shared', handle: 'team@example.com' }] as never,
+};
+
+// Mirrors ConnectedAccountMetadataService's visibility rule: an account is
+// usable by a caller when it is workspace-shared, or it belongs to the caller's
+// own user workspace. The authoritative scoping is proven directly against the
+// repository in connected-account-metadata.service.spec.ts; here we stub the
+// finders so these tests focus on the composer's own selection/rejection logic.
+const isVisibleToCaller = (
+  account: FakeAccount,
+  userWorkspaceId: string | undefined,
+): boolean =>
+  account.visibility === 'workspace' ||
+  (isDefined(userWorkspaceId) && account.userWorkspaceId === userWorkspaceId);
+
+const buildComposeParams = (
+  overrides: Partial<ComposeEmailParams> = {},
+): ComposeEmailParams => ({
+  recipients: { to: 'recipient@example.com' },
+  subject: 'Hello',
+  body: '<p>Hello</p>',
+  ...overrides,
+});
+
+describe('EmailComposerService - connected account authorization', () => {
+  let service: EmailComposerService;
+  let accounts: FakeAccount[];
+
+  beforeEach(async () => {
+    accounts = [
+      aliceUserPrivateAccount,
+      bobUserPrivateAccount,
+      sharedWorkspaceAccount,
+    ];
+
+    const mockConnectedAccountMetadataService = {
+      findAccessibleConnectedAccountById: jest.fn(
+        ({ id, userWorkspaceId, workspaceId }) =>
+          Promise.resolve(
+            accounts.find(
+              (account) =>
+                account.id === id &&
+                account.workspaceId === workspaceId &&
+                isVisibleToCaller(account, userWorkspaceId),
+            ) ?? null,
+          ),
+      ),
+      findAccessibleConnectedAccounts: jest.fn(
+        ({ userWorkspaceId, workspaceId }) => {
+          const accessibleAccounts = accounts.filter(
+            (account) =>
+              account.workspaceId === workspaceId &&
+              isVisibleToCaller(account, userWorkspaceId),
+          );
+
+          return Promise.resolve({
+            userConnectedAccounts: accessibleAccounts.filter(
+              (account) => account.userWorkspaceId === userWorkspaceId,
+            ),
+            workspaceSharedConnectedAccounts: accessibleAccounts.filter(
+              (account) => account.userWorkspaceId !== userWorkspaceId,
+            ),
+          });
+        },
+      ),
+    };
+
+    const mockGlobalWorkspaceOrmManager = {
+      executeInWorkspaceContext: jest
+        .fn()
+        .mockImplementation((fn: () => unknown) => fn()),
+      getRepository: jest.fn(),
+    };
+
+    const mockFileRepository = {
+      find: jest.fn().mockResolvedValue([]),
+    };
+
+    const mockFileService = {
+      getFileStreamById: jest.fn(),
+    };
+
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [
+        EmailComposerService,
+        {
+          provide: GlobalWorkspaceOrmManager,
+          useValue: mockGlobalWorkspaceOrmManager,
+        },
+        {
+          provide: ConnectedAccountMetadataService,
+          useValue: mockConnectedAccountMetadataService,
+        },
+        {
+          provide: getWorkspaceScopedRepositoryToken(FileEntity),
+          useValue: mockFileRepository,
+        },
+        {
+          provide: FileService,
+          useValue: mockFileService,
+        },
+      ],
+    }).compile();
+
+    service = module.get<EmailComposerService>(EmailComposerService);
+  });
+
+  const compose = (params: ComposeEmailParams, context: ToolExecutionContext) =>
+    service.composeEmail(params, context, {
+      attachmentsFileFolder: FileFolder.Workflow,
+    });
+
+  describe('explicit connectedAccountId', () => {
+    it("should reject sending from another member's user-private account (impersonation)", async () => {
+      const bobContext: ToolExecutionContext = {
+        workspaceId: WORKSPACE_ID,
+        userWorkspaceId: BOB_USER_WORKSPACE_ID,
+      };
+
+      // Bob asks to send FROM Alice's private account.
+      await expect(
+        compose(
+          buildComposeParams({
+            connectedAccountId: aliceUserPrivateAccount.id,
+          }),
+          bobContext,
+        ),
+      ).rejects.toThrow();
+    });
+
+    it('should allow a member to use their own user-private account', async () => {
+      const bobContext: ToolExecutionContext = {
+        workspaceId: WORKSPACE_ID,
+        userWorkspaceId: BOB_USER_WORKSPACE_ID,
+      };
+
+      const result = await compose(
+        buildComposeParams({ connectedAccountId: bobUserPrivateAccount.id }),
+        bobContext,
+      );
+
+      expect(result.success).toBe(true);
+      if (result.success) {
+        expect(result.data.connectedAccount.id).toBe(bobUserPrivateAccount.id);
+      }
+    });
+
+    it('should allow any member to use a workspace-visibility account', async () => {
+      const bobContext: ToolExecutionContext = {
+        workspaceId: WORKSPACE_ID,
+        userWorkspaceId: BOB_USER_WORKSPACE_ID,
+      };
+
+      const result = await compose(
+        buildComposeParams({ connectedAccountId: sharedWorkspaceAccount.id }),
+        bobContext,
+      );
+
+      expect(result.success).toBe(true);
+      if (result.success) {
+        expect(result.data.connectedAccount.id).toBe(sharedWorkspaceAccount.id);
+      }
+    });
+  });
+
+  describe('omitted connectedAccountId (default selection)', () => {
+    it("should not silently default to another member's user-private account", async () => {
+      // Only Alice's user-private account exists; Bob has none of his own.
+      accounts = [aliceUserPrivateAccount];
+
+      const bobContext: ToolExecutionContext = {
+        workspaceId: WORKSPACE_ID,
+        userWorkspaceId: BOB_USER_WORKSPACE_ID,
+      };
+
+      await expect(compose(buildComposeParams(), bobContext)).rejects.toThrow();
+    });
+
+    it('should prefer the caller own account over a workspace-visibility account', async () => {
+      const bobContext: ToolExecutionContext = {
+        workspaceId: WORKSPACE_ID,
+        userWorkspaceId: BOB_USER_WORKSPACE_ID,
+      };
+
+      const result = await compose(buildComposeParams(), bobContext);
+
+      expect(result.success).toBe(true);
+      if (result.success) {
+        expect(result.data.connectedAccount.userWorkspaceId).toBe(
+          BOB_USER_WORKSPACE_ID,
+        );
+      }
+    });
+  });
+
+  describe('system/workflow execution without a user identity', () => {
+    it('should reject a user-private account when no userWorkspaceId is present', async () => {
+      const systemContext: ToolExecutionContext = {
+        workspaceId: WORKSPACE_ID,
+      };
+
+      await expect(
+        compose(
+          buildComposeParams({
+            connectedAccountId: aliceUserPrivateAccount.id,
+          }),
+          systemContext,
+        ),
+      ).rejects.toThrow();
+    });
+
+    it('should allow a workspace-visibility account when no userWorkspaceId is present', async () => {
+      const systemContext: ToolExecutionContext = {
+        workspaceId: WORKSPACE_ID,
+      };
+
+      const result = await compose(
+        buildComposeParams({ connectedAccountId: sharedWorkspaceAccount.id }),
+        systemContext,
+      );
+
+      expect(result.success).toBe(true);
+      if (result.success) {
+        expect(result.data.connectedAccount.id).toBe(sharedWorkspaceAccount.id);
+      }
+    });
+  });
+});
diff --git a/packages/twenty-server/src/engine/core-modules/tool/tools/email-tool/email-composer.service.ts b/packages/twenty-server/src/engine/core-modules/tool/tools/email-tool/email-composer.service.ts
index 29f3f90cd8..7c1c012b3a 100644
--- a/packages/twenty-server/src/engine/core-modules/tool/tools/email-tool/email-composer.service.ts
+++ b/packages/twenty-server/src/engine/core-modules/tool/tools/email-tool/email-composer.service.ts
@@ -1,5 +1,4 @@
 import { Injectable, Logger } from '@nestjs/common';
-import { InjectRepository } from '@nestjs/typeorm';
 
 import { toPlainText } from '@react-email/render';
 import { isNonEmptyString } from '@sniptt/guards';
@@ -11,7 +10,7 @@ import {
   FileFolder,
 } from 'twenty-shared/types';
 import { isDefined, isValidUuid } from 'twenty-shared/utils';
-import { In, LessThanOrEqual, type Repository } from 'typeorm';
+import { In, LessThanOrEqual } from 'typeorm';
 import { z } from 'zod';
 
 import { FileEntity } from 'src/engine/core-modules/file/entities/file.entity';
@@ -24,7 +23,7 @@ import { type ComposeEmailParams } from 'src/engine/core-modules/tool/tools/emai
 import { EmailComposerResult } from 'src/engine/core-modules/tool/tools/email-tool/types/email-composer-result.type';
 import { parseCommaSeparatedEmails } from 'src/engine/core-modules/tool/tools/email-tool/utils/parse-comma-separated-emails.util';
 import { type ToolExecutionContext } from 'src/engine/core-modules/tool/types/tool-execution-context.type';
-import { ConnectedAccountEntity } from 'src/engine/metadata-modules/connected-account/entities/connected-account.entity';
+import { ConnectedAccountMetadataService } from 'src/engine/metadata-modules/connected-account/connected-account-metadata.service';
 import { GlobalWorkspaceOrmManager } from 'src/engine/twenty-orm/global-workspace-datasource/global-workspace-orm.manager';
 import { buildSystemAuthContext } from 'src/engine/twenty-orm/utils/build-system-auth-context.util';
 import { InjectWorkspaceScopedRepository } from 'src/engine/twenty-orm/workspace-scoped-repository/inject-workspace-scoped-repository.decorator';
@@ -45,17 +44,21 @@ export class EmailComposerService {
 
   constructor(
     private readonly globalWorkspaceOrmManager: GlobalWorkspaceOrmManager,
-    @InjectRepository(ConnectedAccountEntity)
-    private readonly connectedAccountRepository: Repository<ConnectedAccountEntity>,
+    private readonly connectedAccountMetadataService: ConnectedAccountMetadataService,
     @InjectWorkspaceScopedRepository(FileEntity)
     private readonly fileRepository: WorkspaceScopedRepository<FileEntity>,
     private readonly fileService: FileService,
   ) {}
 
-  private async getConnectedAccount(
-    connectedAccountId: string,
-    workspaceId: string,
-  ) {
+  private async getConnectedAccount({
+    connectedAccountId,
+    workspaceId,
+    userWorkspaceId,
+  }: {
+    connectedAccountId: string;
+    workspaceId: string;
+    userWorkspaceId: string | undefined;
+  }) {
     if (!isValidUuid(connectedAccountId)) {
       throw new EmailToolException(
         `Connected Account ID is not a valid UUID`,
@@ -63,54 +66,63 @@ export class EmailComposerService {
       );
     }
 
-    const authContext = buildSystemAuthContext(workspaceId);
-
-    return this.globalWorkspaceOrmManager.executeInWorkspaceContext(
-      async () => {
-        const connectedAccount = await this.connectedAccountRepository.findOne({
-          where: { id: connectedAccountId, workspaceId },
+    const connectedAccount =
+      await this.connectedAccountMetadataService.findAccessibleConnectedAccountById(
+        {
+          id: connectedAccountId,
+          userWorkspaceId,
+          workspaceId,
           relations: {
             messageChannels: {
               messageFolders: true,
             },
           },
-        });
+        },
+      );
 
-        if (!isDefined(connectedAccount)) {
-          throw new EmailToolException(
-            `Connected Account '${connectedAccountId}' not found`,
-            EmailToolExceptionCode.CONNECTED_ACCOUNT_NOT_FOUND,
-          );
-        }
+    if (!isDefined(connectedAccount)) {
+      throw new EmailToolException(
+        `Connected Account '${connectedAccountId}' not found`,
+        EmailToolExceptionCode.CONNECTED_ACCOUNT_NOT_FOUND,
+      );
+    }
 
-        return connectedAccount;
-      },
-      authContext,
-    );
+    return connectedAccount;
   }
 
-  private async getOrThrowFirstConnectedAccountId(
-    workspaceId: string,
-  ): Promise<string> {
-    const authContext = buildSystemAuthContext(workspaceId);
+  private async getDefaultConnectedAccountOrThrow({
+    workspaceId,
+    userWorkspaceId,
+  }: {
+    workspaceId: string;
+    userWorkspaceId: string | undefined;
+  }) {
+    const { userConnectedAccounts, workspaceSharedConnectedAccounts } =
+      await this.connectedAccountMetadataService.findAccessibleConnectedAccounts(
+        {
+          userWorkspaceId,
+          workspaceId,
+          relations: {
+            messageChannels: {
+              messageFolders: true,
+            },
+          },
+        },
+      );
 
-    return this.globalWorkspaceOrmManager.executeInWorkspaceContext(
-      async () => {
-        const allAccounts = await this.connectedAccountRepository.find({
-          where: { workspaceId },
-        });
+    // Prefer the caller's own account; fall back to a workspace-shared one, but
+    // never silently default to another member's private account.
+    const connectedAccount =
+      userConnectedAccounts[0] ?? workspaceSharedConnectedAccounts[0];
 
-        if (!allAccounts || allAccounts.length === 0) {
-          throw new EmailToolException(
-            'No connected accounts found for this workspace',
-            EmailToolExceptionCode.CONNECTED_ACCOUNT_NOT_FOUND,
-          );
-        }
+    if (!isDefined(connectedAccount)) {
+      throw new EmailToolException(
+        'No connected accounts found for this workspace',
+        EmailToolExceptionCode.CONNECTED_ACCOUNT_NOT_FOUND,
+      );
+    }
 
-        return allAccounts[0].id;
-      },
-      authContext,
-    );
+    return connectedAccount;
   }
 
   private normalizeRecipients(parameters: ComposeEmailParams): {
@@ -314,9 +326,8 @@ export class EmailComposerService {
     context: ToolExecutionContext,
     options: { attachmentsFileFolder: FileFolder },
   ): Promise<EmailComposerResult> {
-    const { workspaceId } = context;
-    const { subject, body, files, inReplyTo } = parameters;
-    let { connectedAccountId } = parameters;
+    const { workspaceId, userWorkspaceId } = context;
+    const { subject, body, files, inReplyTo, connectedAccountId } = parameters;
 
     let recipients: { to: string[]; cc: string[]; bcc: string[] };
 
@@ -352,15 +363,16 @@ export class EmailComposerService {
 
     const toRecipientsDisplay = recipients.to.join(', ');
 
-    if (!connectedAccountId) {
-      connectedAccountId =
-        await this.getOrThrowFirstConnectedAccountId(workspaceId);
-    }
-
-    const connectedAccount = await this.getConnectedAccount(
-      connectedAccountId,
-      workspaceId,
-    );
+    const connectedAccount = isNonEmptyString(connectedAccountId)
+      ? await this.getConnectedAccount({
+          connectedAccountId,
+          workspaceId,
+          userWorkspaceId,
+        })
+      : await this.getDefaultConnectedAccountOrThrow({
+          workspaceId,
+          userWorkspaceId,
+        });
 
     const messageChannel = connectedAccount.messageChannels.find(
       (channel) => channel.handle === connectedAccount.handle,
@@ -375,14 +387,14 @@ export class EmailComposerService {
       !isDefined(connectedAccount.connectionParameters?.SMTP)
     ) {
       throw new EmailToolException(
-        `SMTP is not configured for connected account '${connectedAccountId}'`,
+        `SMTP is not configured for connected account '${connectedAccount.id}'`,
         EmailToolExceptionCode.CONNECTED_ACCOUNT_NOT_FOUND,
       );
     }
 
     if (!isSmtpOnlyAccount && !isDefined(messageChannel)) {
       throw new EmailToolException(
-        `No message channel found for connected account '${connectedAccountId}'`,
+        `No message channel found for connected account '${connectedAccount.id}'`,
         EmailToolExceptionCode.CONNECTED_ACCOUNT_NOT_FOUND,
       );
     }
diff --git a/packages/twenty-server/src/engine/metadata-modules/connected-account/__tests__/connected-account-metadata.service.spec.ts b/packages/twenty-server/src/engine/metadata-modules/connected-account/__tests__/connected-account-metadata.service.spec.ts
new file mode 100644
index 0000000000..43df2b3611
--- /dev/null
+++ b/packages/twenty-server/src/engine/metadata-modules/connected-account/__tests__/connected-account-metadata.service.spec.ts
@@ -0,0 +1,214 @@
+import { randomUUID } from 'node:crypto';
+
+import { Test, type TestingModule } from '@nestjs/testing';
+import { getRepositoryToken } from '@nestjs/typeorm';
+
+import { AppOAuthRevokeService } from 'src/engine/core-modules/application/connection-provider/refresh/services/app-oauth-revoke.service';
+import { CalendarChannelEntity } from 'src/engine/metadata-modules/calendar-channel/entities/calendar-channel.entity';
+import { ConnectedAccountMetadataService } from 'src/engine/metadata-modules/connected-account/connected-account-metadata.service';
+import { ConnectedAccountEntity } from 'src/engine/metadata-modules/connected-account/entities/connected-account.entity';
+import { MessageChannelEntity } from 'src/engine/metadata-modules/message-channel/entities/message-channel.entity';
+
+const WORKSPACE_ID = randomUUID();
+const ALICE_USER_WORKSPACE_ID = randomUUID();
+const BOB_USER_WORKSPACE_ID = randomUUID();
+
+const ALICE_ACCOUNT_ID = randomUUID();
+const BOB_ACCOUNT_ID = randomUUID();
+const SHARED_ACCOUNT_ID = randomUUID();
+
+type FakeAccount = Partial<ConnectedAccountEntity> & { id: string };
+
+const aliceUserPrivateAccount: FakeAccount = {
+  id: ALICE_ACCOUNT_ID,
+  workspaceId: WORKSPACE_ID,
+  userWorkspaceId: ALICE_USER_WORKSPACE_ID,
+  visibility: 'user',
+};
+
+const bobUserPrivateAccount: FakeAccount = {
+  id: BOB_ACCOUNT_ID,
+  workspaceId: WORKSPACE_ID,
+  userWorkspaceId: BOB_USER_WORKSPACE_ID,
+  visibility: 'user',
+};
+
+const sharedWorkspaceAccount: FakeAccount = {
+  id: SHARED_ACCOUNT_ID,
+  workspaceId: WORKSPACE_ID,
+  userWorkspaceId: ALICE_USER_WORKSPACE_ID,
+  visibility: 'workspace',
+};
+
+const matchesWhere = (
+  account: FakeAccount,
+  where: Record<string, unknown> | Record<string, unknown>[],
+): boolean => {
+  const conditions = Array.isArray(where) ? where : [where];
+
+  return conditions.some((condition) =>
+    Object.entries(condition).every(
+      ([key, value]) => account[key as keyof FakeAccount] === value,
+    ),
+  );
+};
+
+describe('ConnectedAccountMetadataService - user-workspace visibility scoping', () => {
+  let service: ConnectedAccountMetadataService;
+  let accounts: FakeAccount[];
+
+  beforeEach(async () => {
+    accounts = [
+      aliceUserPrivateAccount,
+      bobUserPrivateAccount,
+      sharedWorkspaceAccount,
+    ];
+
+    const mockConnectedAccountRepository = {
+      findOne: jest.fn(({ where }) =>
+        Promise.resolve(
+          accounts.find((account) => matchesWhere(account, where)) ?? null,
+        ),
+      ),
+      find: jest.fn(({ where }) =>
+        Promise.resolve(
+          accounts.filter((account) => matchesWhere(account, where)),
+        ),
+      ),
+    };
+
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [
+        ConnectedAccountMetadataService,
+        {
+          provide: getRepositoryToken(ConnectedAccountEntity),
+          useValue: mockConnectedAccountRepository,
+        },
+        {
+          provide: getRepositoryToken(CalendarChannelEntity),
+          useValue: {},
+        },
+        {
+          provide: getRepositoryToken(MessageChannelEntity),
+          useValue: {},
+        },
+        {
+          provide: AppOAuthRevokeService,
+          useValue: {},
+        },
+      ],
+    }).compile();
+
+    service = module.get<ConnectedAccountMetadataService>(
+      ConnectedAccountMetadataService,
+    );
+  });
+
+  describe('findAccessibleConnectedAccountById', () => {
+    it("should not return another member's user-private account", async () => {
+      const result = await service.findAccessibleConnectedAccountById({
+        id: ALICE_ACCOUNT_ID,
+        userWorkspaceId: BOB_USER_WORKSPACE_ID,
+        workspaceId: WORKSPACE_ID,
+      });
+
+      expect(result).toBeNull();
+    });
+
+    it('should return the caller own user-private account', async () => {
+      const result = await service.findAccessibleConnectedAccountById({
+        id: BOB_ACCOUNT_ID,
+        userWorkspaceId: BOB_USER_WORKSPACE_ID,
+        workspaceId: WORKSPACE_ID,
+      });
+
+      expect(result?.id).toBe(BOB_ACCOUNT_ID);
+    });
+
+    it('should return a workspace-visibility account for any member', async () => {
+      const result = await service.findAccessibleConnectedAccountById({
+        id: SHARED_ACCOUNT_ID,
+        userWorkspaceId: BOB_USER_WORKSPACE_ID,
+        workspaceId: WORKSPACE_ID,
+      });
+
+      expect(result?.id).toBe(SHARED_ACCOUNT_ID);
+    });
+
+    it('should reject a user-private account when no userWorkspaceId is present', async () => {
+      const result = await service.findAccessibleConnectedAccountById({
+        id: ALICE_ACCOUNT_ID,
+        userWorkspaceId: undefined,
+        workspaceId: WORKSPACE_ID,
+      });
+
+      expect(result).toBeNull();
+    });
+
+    it('should allow a workspace-visibility account when no userWorkspaceId is present', async () => {
+      const result = await service.findAccessibleConnectedAccountById({
+        id: SHARED_ACCOUNT_ID,
+        userWorkspaceId: undefined,
+        workspaceId: WORKSPACE_ID,
+      });
+
+      expect(result?.id).toBe(SHARED_ACCOUNT_ID);
+    });
+  });
+
+  describe('findAccessibleConnectedAccounts', () => {
+    it("should split the caller own accounts from workspace-shared ones, never exposing another member's private account", async () => {
+      const { userConnectedAccounts, workspaceSharedConnectedAccounts } =
+        await service.findAccessibleConnectedAccounts({
+          userWorkspaceId: BOB_USER_WORKSPACE_ID,
+          workspaceId: WORKSPACE_ID,
+        });
+
+      expect(userConnectedAccounts.map((account) => account.id)).toEqual([
+        BOB_ACCOUNT_ID,
+      ]);
+      expect(
+        workspaceSharedConnectedAccounts.map((account) => account.id),
+      ).toEqual([SHARED_ACCOUNT_ID]);
+    });
+
+    it('should return only workspace-shared accounts when no userWorkspaceId is present', async () => {
+      const { userConnectedAccounts, workspaceSharedConnectedAccounts } =
+        await service.findAccessibleConnectedAccounts({
+          userWorkspaceId: undefined,
+          workspaceId: WORKSPACE_ID,
+        });
+
+      expect(userConnectedAccounts).toEqual([]);
+      expect(
+        workspaceSharedConnectedAccounts.map((account) => account.id),
+      ).toEqual([SHARED_ACCOUNT_ID]);
+    });
+  });
+
+  describe('findByUserWorkspaceId', () => {
+    it('should return only the caller own accounts, including their shared ones', async () => {
+      const result = await service.findByUserWorkspaceId({
+        userWorkspaceId: ALICE_USER_WORKSPACE_ID,
+        workspaceId: WORKSPACE_ID,
+      });
+
+      const ids = result.map((account) => account.id);
+
+      expect(ids).toContain(ALICE_ACCOUNT_ID);
+      expect(ids).toContain(SHARED_ACCOUNT_ID);
+      expect(ids).not.toContain(BOB_ACCOUNT_ID);
+    });
+
+    it('should not return another member workspace-shared account', async () => {
+      const result = await service.findByUserWorkspaceId({
+        userWorkspaceId: BOB_USER_WORKSPACE_ID,
+        workspaceId: WORKSPACE_ID,
+      });
+
+      const ids = result.map((account) => account.id);
+
+      expect(ids).toEqual([BOB_ACCOUNT_ID]);
+    });
+  });
+});
diff --git a/packages/twenty-server/src/engine/metadata-modules/connected-account/connected-account-metadata.service.ts b/packages/twenty-server/src/engine/metadata-modules/connected-account/connected-account-metadata.service.ts
index 1f19c81466..2ef3663322 100644
--- a/packages/twenty-server/src/engine/metadata-modules/connected-account/connected-account-metadata.service.ts
+++ b/packages/twenty-server/src/engine/metadata-modules/connected-account/connected-account-metadata.service.ts
@@ -1,7 +1,13 @@
 import { Injectable, Logger } from '@nestjs/common';
 import { InjectRepository } from '@nestjs/typeorm';
 
-import { Repository } from 'typeorm';
+import {
+  type FindOptionsRelations,
+  type FindOptionsWhere,
+  Repository,
+} from 'typeorm';
+
+import { isDefined } from 'twenty-shared/utils';
 
 import { AppOAuthRevokeService } from 'src/engine/core-modules/application/connection-provider/refresh/services/app-oauth-revoke.service';
 import { CalendarChannelEntity } from 'src/engine/metadata-modules/calendar-channel/entities/calendar-channel.entity';
@@ -34,7 +40,7 @@ export class ConnectedAccountMetadataService {
     workspaceId: string;
   }): Promise<ConnectedAccountEntity[]> {
     return this.repository.find({
-      where: { userWorkspaceId, workspaceId },
+      where: this.getUserConditions({ userWorkspaceId, workspaceId }),
     });
   }
 
@@ -62,6 +68,105 @@ export class ConnectedAccountMetadataService {
     });
   }
 
+  private getUserConditions({
+    id,
+    userWorkspaceId,
+    workspaceId,
+  }: {
+    id?: string;
+    userWorkspaceId: string;
+    workspaceId: string;
+  }): FindOptionsWhere<ConnectedAccountEntity> {
+    return {
+      ...(isDefined(id) ? { id } : {}),
+      workspaceId,
+      userWorkspaceId,
+    };
+  }
+
+  private getWorkspaceSharedConditions({
+    id,
+    workspaceId,
+  }: {
+    id?: string;
+    workspaceId: string;
+  }): FindOptionsWhere<ConnectedAccountEntity> {
+    return {
+      ...(isDefined(id) ? { id } : {}),
+      workspaceId,
+      visibility: 'workspace',
+    };
+  }
+
+  private getAccessibleConditions({
+    id,
+    userWorkspaceId,
+    workspaceId,
+  }: {
+    id?: string;
+    userWorkspaceId: string | undefined;
+    workspaceId: string;
+  }): FindOptionsWhere<ConnectedAccountEntity>[] {
+    const workspaceSharedConditions = this.getWorkspaceSharedConditions({
+      id,
+      workspaceId,
+    });
+
+    if (!isDefined(userWorkspaceId)) {
+      return [workspaceSharedConditions];
+    }
+
+    return [
+      this.getUserConditions({ id, userWorkspaceId, workspaceId }),
+      workspaceSharedConditions,
+    ];
+  }
+
+  async findAccessibleConnectedAccounts({
+    userWorkspaceId,
+    workspaceId,
+    relations,
+  }: {
+    userWorkspaceId: string | undefined;
+    workspaceId: string;
+    relations?: FindOptionsRelations<ConnectedAccountEntity>;
+  }): Promise<{
+    userConnectedAccounts: ConnectedAccountEntity[];
+    workspaceSharedConnectedAccounts: ConnectedAccountEntity[];
+  }> {
+    const accounts = await this.repository.find({
+      where: this.getAccessibleConditions({ workspaceId, userWorkspaceId }),
+      relations,
+      order: { createdAt: 'ASC' },
+    });
+
+    return {
+      userConnectedAccounts: accounts.filter(
+        (account) => account.userWorkspaceId === userWorkspaceId,
+      ),
+      workspaceSharedConnectedAccounts: accounts.filter(
+        (account) => account.userWorkspaceId !== userWorkspaceId,
+      ),
+    };
+  }
+
+  async findAccessibleConnectedAccountById({
+    id,
+    userWorkspaceId,
+    workspaceId,
+    relations,
+  }: {
+    id: string;
+    userWorkspaceId: string | undefined;
+    workspaceId: string;
+    relations?: FindOptionsRelations<ConnectedAccountEntity>;
+  }): Promise<ConnectedAccountEntity | null> {
+    return this.repository.findOne({
+      where: this.getAccessibleConditions({ workspaceId, userWorkspaceId, id }),
+      relations,
+    });
+  }
+
   async verifyOwnership({
     id,
     userWorkspaceId,
@@ -103,7 +208,7 @@ export class ConnectedAccountMetadataService {
     workspaceId: string;
   }): Promise<string[]> {
     const accounts = await this.repository.find({
-      where: { userWorkspaceId, workspaceId },
+      where: this.getUserConditions({ userWorkspaceId, workspaceId }),
       select: ['id'],
     });
 
@@ -116,7 +221,7 @@ export class ConnectedAccountMetadataService {
     workspaceId: string;
   }): Promise<string[]> {
     const accounts = await this.repository.find({
-      where: { workspaceId, visibility: 'workspace' },
+      where: this.getWorkspaceSharedConditions({ workspaceId }),
       select: ['id'],
     });
 
diff --git a/packages/twenty-server/src/modules/messaging/message-outbound-manager/resolvers/send-email.resolver.ts b/packages/twenty-server/src/modules/messaging/message-outbound-manager/resolvers/send-email.resolver.ts
index 19bd41d51d..4f76ff881c 100644
--- a/packages/twenty-server/src/modules/messaging/message-outbound-manager/resolvers/send-email.resolver.ts
+++ b/packages/twenty-server/src/modules/messaging/message-outbound-manager/resolvers/send-email.resolver.ts
@@ -69,7 +69,7 @@ export class SendEmailResolver {
           files: input.files ?? [],
           inReplyTo: input.inReplyTo,
         },
-        { workspaceId: workspace.id },
+        { workspaceId: workspace.id, userWorkspaceId },
         { attachmentsFileFolder: FileFolder.EmailAttachment },
       );
 
diff --git a/packages/twenty-server/test/integration/metadata/suites/connected-account/connected-account-resolver.integration-spec.ts b/packages/twenty-server/test/integration/metadata/suites/connected-account/connected-account-resolver.integration-spec.ts
index 8a56501677..5d9695fe4a 100644
--- a/packages/twenty-server/test/integration/metadata/suites/connected-account/connected-account-resolver.integration-spec.ts
+++ b/packages/twenty-server/test/integration/metadata/suites/connected-account/connected-account-resolver.integration-spec.ts
@@ -118,4 +118,37 @@ describe('connectedAccountResolver (e2e)', () => {
       expect(response.body.errors?.[0]?.extensions?.code).toBe('FORBIDDEN');
     });
   });
+
+  describe('sendEmail', () => {
+    it("should reject sending from another member's connected account", async () => {
+      const response = await makeMetadataAPIRequest({
+        query: gql`
+          mutation SendEmail($input: SendEmailInput!) {
+            sendEmail(input: $input) {
+              success
+              error
+            }
+          }
+        `,
+        variables: {
+          input: {
+            connectedAccountId: CONNECTED_ACCOUNT_DATA_SEED_IDS.JONY,
+            to: 'recipient@example.com',
+            subject: 'Should never be sent',
+            body: '<p>Should never be sent</p>',
+          },
+        },
+      });
+
+      expect(response.status).toBe(200);
+      expect(response.body.errors).toBeUndefined();
+
+      const result = response.body.data.sendEmail;
+
+      expect(result.success).toBe(false);
+      expect(result.error).toMatchInlineSnapshot(
+        `"Connected account 20202020-0cc8-4d60-a3a4-803245698908 does not belong to user workspace 20202020-1e7c-43d9-a5db-685b5069d816"`,
+      );
+    });
+  });
 });