From 6fe9f8f7f15f63de11962c9b0ea271ff20344903 Mon Sep 17 00:00:00 2001
From: Ali Yousuf <aly.yousuf7@gmail.com>
Date: Sat, 17 Oct 2026 18:41:31 -0400
Subject: [PATCH] fix: let api.email.get read a listed message of a shared
 account

doEmailGet asked the signed-in account for every id, so a message in a
folder shared from another account came back as null even though it was
in the list. A message in the loaded list is now read from the account
that owns it, through resolveEmailBlobContext like attachment downloads.
getAttachment and getRaw keep reading from the signed-in account only.

Fixes #1273
---
 lib/__tests__/plugin-host-mail-read.test.ts | 10 +++++++++-
 lib/plugin-sandbox/host-api-mail.ts         | 16 ++++++++++++----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/lib/__tests__/plugin-host-mail-read.test.ts b/lib/__tests__/plugin-host-mail-read.test.ts
index 9db3e13b1..a7ed397c4 100644
--- a/lib/__tests__/plugin-host-mail-read.test.ts
+++ b/lib/__tests__/plugin-host-mail-read.test.ts
@@ -54,7 +54,7 @@ beforeEach(() => {
 
 afterEach(() => {
   useAuthStore.setState({ client: null });
-  useEmailStore.setState({ mailboxes: [], selectedEmail: null });
+  useEmailStore.setState({ mailboxes: [], selectedEmail: null, selectedMailbox: '', emails: [] });
 });
 
 describe('api.email.get', () => {
@@ -67,6 +67,14 @@ describe('api.email.get', () => {
     expect(await call(READER, 'email.get', 'gone')).toBeNull();
   });
 
+  it('asks the owning account for a listed message of a shared folder', async () => {
+    client.getEmail.mockImplementation(async (id: string, accountId?: string) => (
+      id === 's1' && accountId === 'acc2' ? mail('s1', { subject: 'Shared' }) : null));
+    useEmailStore.setState({ selectedMailbox: 'acc2:box', emails: [mail('s1', { mailboxIds: { 'acc2:box': true } })] });
+    expect(await call(READER, 'email.get', 's1')).toEqual(expect.objectContaining({ id: 's1', subject: 'Shared' }));
+    expect(client.getEmail).toHaveBeenCalledWith('s1', 'acc2');
+  });
+
   it('uses the open message when its body is loaded', async () => {
     useEmailStore.setState({ selectedEmail: mail('open', { bodyValues: { 1: { value: 'x' } }, textBody: [{ partId: '1' }] } as unknown as Partial<Email>) });
     expect(await call(READER, 'email.get', 'open')).toEqual(expect.objectContaining({ id: 'open', text: 'x' }));
diff --git a/lib/plugin-sandbox/host-api-mail.ts b/lib/plugin-sandbox/host-api-mail.ts
index 4c2fb4ee8..33d4d7389 100644
--- a/lib/plugin-sandbox/host-api-mail.ts
+++ b/lib/plugin-sandbox/host-api-mail.ts
@@ -3,13 +3,14 @@
 // (api.email.getAttachment / getRaw). Reads go to the server through the
 // JMAP client and never change what the user has open.
 //
-// Messages are read from the signed-in account itself; mail in folders shared
-// from other accounts is not reached by id here.
+// api.email.get also reads a message of a shared account when it is in the
+// loaded list, from the account that owns it. The bytes of attachments and
+// sources are read from the signed-in account only.
 
 import type { EmailReadView, EmailSummary, MailboxView } from '../plugin-types';
 import type { Email, Mailbox } from '../jmap/types';
 import type { IJMAPClient } from '../jmap/client-interface';
-import { useEmailStore } from '@/stores/email-store';
+import { resolveEmailBlobContext, useEmailStore } from '@/stores/email-store';
 import { emailSummary, emailToReadView } from '../plugin-projection';
 import {
   MAX_PLUGIN_FETCH_BYTES, readId, readInteger, readObject, sessionClient, withinRate,
@@ -30,7 +31,14 @@ async function loadEmail(client: IJMAPClient, emailId: string): Promise<Email |
 export async function doEmailGet(id: unknown): Promise<EmailReadView | null> {
   const method = 'email.get';
   const emailId = readId(id, method, 'emailId');
-  const email = await loadEmail(sessionClient(method), emailId);
+  const client = sessionClient(method);
+  // A listed message of a shared account is asked of the account that owns
+  // it; the signed-in account doesn't know its id.
+  const listed = useEmailStore.getState().emails.find((e) => e.id === emailId);
+  const owner = listed ? resolveEmailBlobContext(listed, client) : null;
+  const email = owner?.client && owner.accountId
+    ? await owner.client.getEmail(emailId, owner.accountId)
+    : await loadEmail(client, emailId);
   return email ? emailToReadView(email) : null;
 }