fix: send group mail through the group's identity on Send now and quick reply

src/api/__tests__/email-submission.test.ts

@@ -107,7 +107,7 @@ describe('rescheduleScheduledSend', () => {
     expect(result).toEqual({ emailSubmissionId: 'sub-2', sendAt: '2026-09-25T08:00:00Z' });
     const [lookup] = mockRequest.mock.calls[0][0];
     expect(lookup).toEqual([
-      'EmailSubmission/get', { accountId: 'acc-1', ids: ['sub-1'], properties: ['envelope', 'sendAt'] }, '0',
+      'EmailSubmission/get', { accountId: 'acc-1', ids: ['sub-1'], properties: ['envelope', 'sendAt', 'identityId'] }, '0',
     ]);
     expect(createdArgs().create.replacement.envelope).toEqual({
       mailFrom: { email: 'me@example.com', parameters: { HOLDFOR: '7200' } },
@@ -218,6 +218,37 @@ describe('rescheduleScheduledSend', () => {
     vi.mocked(Date.now).mockRestore();
   });
 
+  // A group send's undo entry carried the login's own identity id, which
+  // names nothing in the group account: both creates were refused and the
+  // message went back to Drafts unsent.
+  it("submits the replacement and the put-back through the original's identity, not the caller's", async () => {
+    const lookup = structuredClone(LOOKUP);
+    (lookup.methodResponses[0][1] as { list: Array<Record<string, unknown>> }).list[0].identityId = 'grp-identity';
+    mockRequest
+      .mockResolvedValueOnce(lookup)
+      .mockResolvedValueOnce(CANCELLED)
+      .mockResolvedValueOnce(DESTROYED('sub-1'))
+      .mockResolvedValueOnce(REFUSED('Quota exceeded'))
+      .mockResolvedValueOnce(set({ created: { replacement: { id: 'sub-3' } } }));
+
+    await rescheduleScheduledSend({ ...SCHEDULED, identityId: 'own-identity', accountId: 'grp-1' }, 0).catch(() => undefined);
+
+    expect(createdArgs(0).create.replacement.identityId).toBe('grp-identity');
+    expect(createdArgs(1).create.replacement.identityId).toBe('grp-identity');
+  });
+
+  it("keeps the caller's identity when the server does not name one", async () => {
+    mockRequest
+      .mockResolvedValueOnce(LOOKUP)
+      .mockResolvedValueOnce(CANCELLED)
+      .mockResolvedValueOnce(DESTROYED('sub-1'))
+      .mockResolvedValueOnce({ methodResponses: REPLACED });
+
+    await rescheduleScheduledSend(SCHEDULED, 0);
+
+    expect(createdArgs().create.replacement.identityId).toBe('id-1');
+  });
+
   it('moves the message back to Drafts when neither the replacement nor the original can be made', async () => {
     vi.spyOn(console, 'warn').mockImplementation(() => undefined);
     mockRequest

src/api/email.ts

@@ -2230,7 +2230,7 @@ export async function rescheduleScheduledSend(
   const lookup = await jmapClient.request(
     [
       ['EmailSubmission/get', {
-        accountId, ids: [scheduled.emailSubmissionId], properties: ['envelope', 'sendAt'],
+        accountId, ids: [scheduled.emailSubmissionId], properties: ['envelope', 'sendAt', 'identityId'],
       }, '0'],
       ['Email/get', { accountId, ids: [scheduled.emailId], properties: ['to', 'cc', 'bcc'] }, '1'],
       ['Mailbox/get', { accountId, ids: null, properties: ['id', 'role'] }, '2'],
@@ -2240,8 +2240,14 @@ export async function rescheduleScheduledSend(
   const original = (requireMethodResult(lookup, '0', 'EmailSubmission/get').list as Array<{
     envelope?: { mailFrom?: { email?: string }; rcptTo?: Array<{ email?: string }> } | null;
     sendAt?: string;
+    identityId?: string;
   }> | undefined)?.[0];
   const envelope = original?.envelope;
+  // The original's identity is one of the submission account's. The caller's
+  // may be the composer's, from the login's own account: for a group
+  // identity's message that id names nothing in the group account, and the
+  // replacement and the put-back were both refused (webmail parity).
+  const identityId = original?.identityId || scheduled.identityId;
   const held = requireMethodResult(lookup, '1', 'Email/get').list as Email[] | undefined;
   const headerRecipients = [...(held?.[0]?.to ?? []), ...(held?.[0]?.cc ?? []), ...(held?.[0]?.bcc ?? [])];
   const source = recipients ?? (envelope?.rcptTo?.length ? envelope.rcptTo : headerRecipients);
@@ -2271,7 +2277,7 @@ export async function rescheduleScheduledSend(
             create: {
               replacement: {
                 emailId: scheduled.emailId,
-                identityId: scheduled.identityId,
+                identityId,
                 envelope: {
                   mailFrom: seconds === undefined
                     ? { email: mailFrom }

src/components/email/QuickReplyBox.tsx

@@ -22,7 +22,7 @@ import { resolveReplyIdentity } from '../../lib/reply-identity';
 import { signatureIdentityFor, signPlainTextReply } from '../../lib/signature-utils';
 import { pickEmailBody, plainTextBody } from '../../lib/email-body';
 import { htmlToPlainText } from '../../lib/compose-html';
-import { mailboxesOfAccount } from '../../lib/mailbox-tree';
+import { sendTargetFor } from '../../lib/compose-send-account';
 import { emailDisplayDate } from '../../lib/email-date';
 import { buildQuoteHeader, quoteHeaderLabels } from '../../lib/quote-header';
 
@@ -66,16 +66,19 @@ export function QuickReplyBox({ email, jmapAccountId, onMoreOptions, onSent, onF
   const from = email.from?.[0];
   if (!from?.email || email.keywords?.$draft) return null;
 
+  const refuseAfterSwitch = () => {
+    if (!loginMovedFrom(ownerLoginRef.current)) return false;
+    Alert.alert(
+      t('email_composer.login_switched_title', 'Account switched'),
+      t('email_viewer.quick_reply_login_switched', 'This message is in another account. Switch back to it to reply.'),
+    );
+    return true;
+  };
+
   const send = async () => {
     const body = text.trim();
     if (!body || sending) return;
-    if (loginMovedFrom(ownerLoginRef.current)) {
+    if (refuseAfterSwitch()) return;
-      Alert.alert(
-        t('email_composer.login_switched_title', 'Account switched'),
-        t('email_viewer.quick_reply_login_switched', 'This message is in another account. Switch back to it to reply.'),
-      );
-      return;
-    }
     const ownEmails = identities.map((i) => i.email).filter(Boolean);
     // The own identity the message was delivered to (or, for our own message,
     // the one that sent it). Never the catch-all From rewrite: this box has no
@@ -88,16 +91,20 @@ export function QuickReplyBox({ email, jmapAccountId, onMoreOptions, onSent, onF
       Alert.alert(t('common.error', 'Error'), t('email_viewer.unsubscribe_banner.no_identity', 'No sending identity available'));
       return;
     }
-    // Sent/Drafts of the account the reply is submitted from: the message's.
-    const scoped = mailboxesOfAccount(mailboxes, jmapAccountId);
-    const sent = scoped.find((m) => m.role === 'sent');
-    const drafts = scoped.find((m) => m.role === 'drafts');
-    if (!sent) {
-      Alert.alert(t('common.error', 'Error'), t('email_composer.no_sent_folder', 'No Sent folder found'));
-      return;
-    }
     setSending(true);
     try {
+      // The account, identity and folders the reply goes out through, as the
+      // composer picks them (#1090): a group address sends from the group's
+      // account with that account's identity id. The message's own account
+      // with the login's identity id named nothing there, or another
+      // identity.
+      const target = await sendTargetFor(identity, identity.email, mailboxes);
+      if (!target.sentMailboxId) {
+        Alert.alert(t('common.error', 'Error'), t('email_composer.no_sent_folder', 'No Sent folder found'));
+        return;
+      }
+      // The lookup may have outlasted a switch of logins.
+      if (refuseAfterSwitch()) return;
       const recipients = buildReplyRecipients(
         { from: email.from, replyToAddresses: email.replyTo, to: email.to, cc: email.cc },
         'reply',
@@ -116,10 +123,10 @@ export function QuickReplyBox({ email, jmapAccountId, onMoreOptions, onSent, onF
         labels: quoteHeaderLabels(t),
       });
       const threading = computeReplyThreadingHeaders(email);
-      const holdFor = jmapClient.undoSendHold(sendDelaySeconds, jmapAccountId);
+      const holdFor = jmapClient.undoSendHold(sendDelaySeconds, target.accountId);
       // Where the reply goes, read before it goes: Undo must reach that login
       // and account whatever the app switches to meanwhile.
-      const sentThrough = { login: currentSendLogin(), accountId: jmapAccountId ?? jmapClient.connectedAccountId ?? undefined };
+      const sentThrough = { login: currentSendLogin(), accountId: target.accountId ?? jmapClient.connectedAccountId ?? undefined };
       const result = await sendEmail(
         {
           from: [{ name: identity.name, email: identity.email }],
@@ -135,15 +142,15 @@ export function QuickReplyBox({ email, jmapAccountId, onMoreOptions, onSent, onF
           inReplyTo: threading?.inReplyTo,
           references: threading?.references,
         },
-        identity.id,
+        target.identityId,
-        sent.originalId ?? sent.id,
+        target.sentMailboxId,
         holdFor,
-        { draftsMailboxId: drafts ? (drafts.originalId ?? drafts.id) : undefined, accountId: jmapAccountId },
+        { draftsMailboxId: target.draftsMailboxId, accountId: target.accountId },
       );
       // Held for the undo-send delay: the undo bar offers Undo / Send now.
       // Recorded before the flag below so its round trip doesn't eat the window.
       useSendUndoStore.getState().recordHeldSend(result, holdFor, {
-        identityId: identity.id,
+        identityId: target.identityId,
         ...sentThrough,
         from: [{ name: identity.name, email: identity.email }],
       });

src/lib/__tests__/compose-send-target-wiring.test.ts

@@ -0,0 +1,29 @@
+import { describe, expect, it } from 'vitest';
+import fs from 'node:fs';
+import path from 'node:path';
+
+// A group or shared identity sends from the group's account with that
+// account's identity id (lib/compose-send-account). Both places below used
+// the login's own identity id, which names nothing in the group account:
+// "Send now" from the undo bar lost the message, and a quick reply was
+// refused or went out through another identity.
+const read = (rel: string) => fs.readFileSync(path.resolve(__dirname, rel), 'utf8');
+
+describe('send target wiring', () => {
+  it("records the target's identity for the undo bar of a composer send", () => {
+    const source = read('../../screens/ComposeScreen.tsx');
+    const held = source.slice(source.indexOf('recordHeldSend(result, holdForSeconds'));
+    expect(held).toMatch(/^recordHeldSend\(result, holdForSeconds, \{[\s\S]*?identityId: target\.identityId,/);
+    expect(held.slice(0, 300)).not.toContain('primaryIdentity.id');
+  });
+
+  it('sends a quick reply through the target the composer would pick', () => {
+    const source = read('../../components/email/QuickReplyBox.tsx');
+    expect(source).toMatch(/const target = await sendTargetFor\(identity, identity\.email, mailboxes\)/);
+    const call = source.slice(source.indexOf('await sendEmail('));
+    expect(call).toMatch(/\},\s+target\.identityId,\s+target\.sentMailboxId,/);
+    expect(call).toMatch(/accountId: target\.accountId \}/);
+    expect(source).toMatch(/recordHeldSend\(result, holdFor, \{\s*identityId: target\.identityId,/);
+    expect(source).not.toMatch(/identity\.id,\s+sent\./);
+  });
+});

src/screens/ComposeScreen.tsx

@@ -2407,7 +2407,9 @@ export default function ComposeScreen({ route, navigation }: Props) {
       } else if (result.scheduled) {
         // Undo-send window: the undo bar offers Undo / Send now.
         useSendUndoStore.getState().recordHeldSend(result, holdForSeconds, {
-          identityId: primaryIdentity.id,
+          // The identity the message went out through, as the submission
+          // account names it: "Send now" submits again with it.
+          identityId: target.identityId,
           accountId: submissionAccountId,
           login: ownerLoginRef.current,
           from: outgoing.from,