diff --git a/components/email/__tests__/placeholder-warning.test.tsx b/components/email/__tests__/placeholder-warning.test.tsx
new file mode 100644
index 000000000..0cda741ea
--- /dev/null
+++ b/components/email/__tests__/placeholder-warning.test.tsx
@@ -0,0 +1,332 @@
+import { render, screen, fireEvent, waitFor, within } from '@testing-library/react';
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import React from 'react';
+import { EmailComposer } from '../email-composer';
+import { useSettingsStore } from '@/stores/settings-store';
+
+// ─── Heavy component mocks (mirrors empty-subject-warning.test.tsx) ──────────
+
+vi.mock('@/components/email/rich-text-editor', () => ({
+  RichTextEditor: () => React.createElement('div', { 'data-testid': 'rich-text-editor' }),
+}));
+
+vi.mock('@/components/plugins/plugin-slot', () => ({ PluginSlot: () => null }));
+vi.mock('@/components/identity/sub-address-helper', () => ({ SubAddressHelper: () => null }));
+vi.mock('@/components/templates/template-picker', () => ({ TemplatePicker: () => null }));
+vi.mock('@/components/templates/template-form', () => ({ TemplateForm: () => null }));
+vi.mock('@/components/files/file-preview-modal', () => ({ FilePreviewModal: () => null }));
+vi.mock('@/hooks/use-focus-trap', () => ({
+  useFocusTrap: () => ({ current: null }),
+}));
+vi.mock('@/hooks/use-pro-multi-account-identities', () => ({
+  useProMultiAccountIdentities: () => ({ enabled: false, groups: [], allIdentities: [] }),
+  stripCrossAccountIdentityPrefix: (id: string) => ({ localAccountId: null, rawId: id }),
+}));
+
+// ─── Store mocks ──────────────────────────────────────────────────────────────
+
+vi.mock('@/stores/auth-store', () => {
+  const state = {
+    client: null,
+    identities: [],
+    primaryIdentity: null,
+    isAuthenticated: false,
+    isDemoMode: false,
+    activeAccountId: null,
+    connectionLost: false,
+    getClientForAccount: () => undefined,
+    getAllConnectedClients: () => new Map(),
+    syncIdentities: () => {},
+    refreshIdentities: async () => {},
+  };
+  const hook = (sel?: (s: typeof state) => unknown) =>
+    typeof sel === 'function' ? sel(state) : state;
+  hook.getState = () => state;
+  hook.setState = (p: Partial<typeof state>) => Object.assign(state, p);
+  return { useAuthStore: hook };
+});
+
+vi.mock('@/stores/identity-store', () => {
+  const state = {
+    identities: [{ id: 'id-me', email: 'me@example.com', name: 'Me' }],
+    defaultIdentityId: 'id-me',
+  };
+  const hook = (sel?: (s: typeof state) => unknown) =>
+    typeof sel === 'function' ? sel(state) : state;
+  hook.getState = () => state;
+  hook.setState = (p: Partial<typeof state>) => Object.assign(state, p);
+  return { useIdentityStore: hook };
+});
+
+vi.mock('@/stores/account-store', () => {
+  const state = { accounts: [], getAccountById: () => undefined };
+  const hook = (sel?: (s: typeof state) => unknown) =>
+    typeof sel === 'function' ? sel(state) : state;
+  hook.getState = () => state;
+  hook.setState = (p: Partial<typeof state>) => Object.assign(state, p);
+  return { useAccountStore: hook };
+});
+
+vi.mock('@/stores/email-store', () => {
+  const state = {
+    draftSaveEnabled: false,
+    sendRawEmail: async () => ({ sent: true }),
+  };
+  const hook = (sel?: (s: typeof state) => unknown) =>
+    typeof sel === 'function' ? sel(state) : state;
+  hook.getState = () => state;
+  hook.setState = (p: Partial<typeof state>) => Object.assign(state, p);
+  return { useEmailStore: hook };
+});
+
+const updateSetting = vi.fn();
+
+vi.mock('@/stores/settings-store', () => {
+  const state = {
+    timeFormat: '24h',
+    plainTextMode: false,
+    subAddressDelimiter: '+',
+    autoSelectReplyIdentity: true,
+    attachmentReminderEnabled: false,
+    attachmentReminderKeywords: [],
+    emptySubjectWarningEnabled: true,
+    placeholderWarningEnabled: true,
+    sendDelaySeconds: 0,
+    signaturePosition: 'above_quote',
+    signatureSeparatorEnabled: false,
+    requestReadReceiptDefault: false,
+    addTrustedSender: () => {},
+    trustedSendersAddressBook: null,
+    updateSetting: (...args: unknown[]) => updateSetting(...args),
+  };
+  const hook = (sel?: (s: typeof state) => unknown) =>
+    typeof sel === 'function' ? sel(state) : state;
+  hook.getState = () => state;
+  hook.setState = (p: Partial<typeof state>) => Object.assign(state, p);
+  return { useSettingsStore: hook };
+});
+
+vi.mock('@/stores/contact-store', () => {
+  const state = {
+    contacts: [],
+    getAutocomplete: async () => [],
+    addToTrustedSendersBook: async () => {},
+  };
+  const hook = (sel?: (s: typeof state) => unknown) =>
+    typeof sel === 'function' ? sel(state) : state;
+  hook.getState = () => state;
+  hook.setState = (p: Partial<typeof state>) => Object.assign(state, p);
+  return { useContactStore: hook };
+});
+
+vi.mock('@/stores/template-store', () => {
+  const state = { templates: [], addTemplate: async () => {} };
+  const hook = (sel?: (s: typeof state) => unknown) =>
+    typeof sel === 'function' ? sel(state) : state;
+  hook.getState = () => state;
+  hook.setState = (p: Partial<typeof state>) => Object.assign(state, p);
+  return { useTemplateStore: hook };
+});
+
+// ─── Misc dependency mocks ────────────────────────────────────────────────────
+
+vi.mock('@/stores/toast-store', () => ({
+  toast: { info: () => {}, error: () => {}, success: () => {} },
+}));
+
+vi.mock('@/lib/plugin-hooks', () => ({
+  identityHooks: {
+    onSignatureRender: { size: 0, transform: async (value: unknown) => value },
+    onIdentitySelect: { size: 0, emit: async () => {} },
+  },
+  templateHooks: {
+    onTemplateRender: { size: 0, transform: async (value: unknown) => value },
+    onTemplateApply: { size: 0, emit: async () => {} },
+  },
+  emailHooks: {
+    onComposerOpen: { call: async () => [] },
+    onRecipientChange: { call: async () => [] },
+    getRecipientSuggestions: { call: async () => [] },
+    onRecipientChipsChange: { transform: async (chips: unknown) => chips },
+    onDraftChange: { emit: () => {} },
+    onBeforeDraftAutoSave: { transform: async (draft: unknown) => draft },
+    onBeforeEmailSend: { intercept: async () => true, interceptOutcome: async () => 'allowed' },
+    onComposeSend: { takeOver: async () => 'default' },
+    onTransformOutgoingEmail: { transform: async (email: unknown) => email },
+  },
+  contactHooks: {
+    search: { call: async () => [] },
+    onProvideRecipientSuggestions: { transform: async (initial: unknown) => initial },
+  },
+}));
+
+vi.mock('@/lib/email-sanitization', () => ({
+  sanitizeSignatureHtml: (v: string) => v,
+  sanitizeEmailHtml: (v: string) => v,
+  parseHtmlSafely: (html: string) => new DOMParser().parseFromString(html, 'text/html'),
+}));
+
+vi.mock('@/lib/email-threading', () => ({
+  computeReplyThreadingHeaders: () => ({ inReplyTo: [], references: [] }),
+}));
+vi.mock('@/lib/signature-utils', () => ({
+  appendPlainTextSignature: (body: string) => body,
+  getPlainTextSignature: () => '',
+  plainTextBodyWithoutSignature: (body: string) => body,
+}));
+vi.mock('@/lib/sub-addressing', () => ({ generateSubAddress: () => '' }));
+vi.mock('@/lib/debug', () => ({ debug: { log: () => {}, warn: () => {}, error: () => {} } }));
+vi.mock('@/components/email/quoted-html', () => ({
+  buildQuotedHtmlBlock: () => '',
+  serializeEditorContent: () => '',
+}));
+vi.mock('@/lib/template-utils', () => ({ substitutePlaceholders: (s: string) => s }));
+
+// ─── Tests ────────────────────────────────────────────────────────────────────
+
+/** A ready-to-send draft whose body still has a fill-in. */
+const DRAFT_WITH_PLACEHOLDER = {
+  to: 'bob@example.com',
+  cc: '',
+  bcc: '',
+  subject: 'Lunch',
+  body: '<p>See you at [TIME] in TODO.</p>',
+  showCc: false,
+  showBcc: false,
+  selectedIdentityId: 'id-me',
+  subAddressTag: '',
+  mode: 'compose' as const,
+  draftId: null,
+};
+
+const sendButton = () => screen.getAllByTestId('composer-send')[0] as HTMLButtonElement;
+
+describe('composer placeholder warning', () => {
+  beforeEach(() => {
+    updateSetting.mockClear();
+  });
+
+  afterEach(() => {
+    useSettingsStore.setState({
+      placeholderWarningEnabled: true,
+      attachmentReminderEnabled: false,
+      attachmentReminderKeywords: [],
+    } as never);
+  });
+
+  it('asks before sending and lists the placeholders', async () => {
+    const onSend = vi.fn();
+    render(<EmailComposer initialData={DRAFT_WITH_PLACEHOLDER} onSend={onSend} />);
+
+    fireEvent.click(sendButton());
+
+    const dialog = await screen.findByRole('alertdialog');
+    expect(within(dialog).getByText('placeholder_warning.title')).toBeInTheDocument();
+    const found = within(dialog).getAllByRole('listitem').map((li) => li.textContent);
+    expect(found).toEqual(['[TIME]', 'TODO']);
+    expect(onSend).not.toHaveBeenCalled();
+  });
+
+  it('sends once confirmed', async () => {
+    const onSend = vi.fn();
+    render(<EmailComposer initialData={DRAFT_WITH_PLACEHOLDER} onSend={onSend} />);
+
+    fireEvent.click(sendButton());
+    fireEvent.click(await screen.findByText('placeholder_warning.send_anyway'));
+
+    await waitFor(() => expect(onSend).toHaveBeenCalledTimes(1));
+    expect(updateSetting).not.toHaveBeenCalled();
+  });
+
+  it('turns the warning off when "don\'t ask again" is checked', async () => {
+    const onSend = vi.fn();
+    render(<EmailComposer initialData={DRAFT_WITH_PLACEHOLDER} onSend={onSend} />);
+
+    fireEvent.click(sendButton());
+    fireEvent.click(await screen.findByText('placeholder_warning.dont_ask_again'));
+    fireEvent.click(screen.getByText('placeholder_warning.send_anyway'));
+
+    await waitFor(() => expect(onSend).toHaveBeenCalledTimes(1));
+    expect(updateSetting).toHaveBeenCalledWith('placeholderWarningEnabled', false);
+  });
+
+  it('goes back to editing with the placeholder selected', async () => {
+    const onSend = vi.fn();
+    render(
+      <EmailComposer
+        initialData={{ ...DRAFT_WITH_PLACEHOLDER, subject: 'Hi {{name}}', body: '<p>Hello</p>' }}
+        onSend={onSend}
+      />
+    );
+
+    fireEvent.click(sendButton());
+    fireEvent.click(await screen.findByText('placeholder_warning.back'));
+
+    await waitFor(() => expect(screen.queryByRole('alertdialog')).not.toBeInTheDocument());
+    const subject = screen.getByDisplayValue('Hi {{name}}') as HTMLInputElement;
+    await waitFor(() => expect(document.activeElement).toBe(subject));
+    expect([subject.selectionStart, subject.selectionEnd]).toEqual([3, 11]);
+    expect(onSend).not.toHaveBeenCalled();
+  });
+
+  it('does not ask again after Send anyway and a trip back to add an attachment', async () => {
+    useSettingsStore.setState({ attachmentReminderEnabled: true, attachmentReminderKeywords: ['see you'] } as never);
+    const onSend = vi.fn();
+    render(<EmailComposer initialData={DRAFT_WITH_PLACEHOLDER} onSend={onSend} />);
+
+    fireEvent.click(sendButton());
+    fireEvent.click(await screen.findByText('placeholder_warning.send_anyway'));
+    // The body says "See you", so the attachment reminder stops the send.
+    fireEvent.click(await screen.findByText('forgot_attachment.back'));
+    await waitFor(() => expect(screen.queryByText('forgot_attachment.title')).not.toBeInTheDocument());
+
+    fireEvent.click(sendButton());
+
+    expect(await screen.findByText('forgot_attachment.title')).toBeInTheDocument();
+    expect(screen.queryByText('placeholder_warning.title')).not.toBeInTheDocument();
+    expect(onSend).not.toHaveBeenCalled();
+  });
+
+  it('asks again when a new placeholder shows up', async () => {
+    useSettingsStore.setState({ attachmentReminderEnabled: true, attachmentReminderKeywords: ['see you'] } as never);
+    const onSend = vi.fn();
+    render(<EmailComposer initialData={DRAFT_WITH_PLACEHOLDER} onSend={onSend} />);
+
+    fireEvent.click(sendButton());
+    fireEvent.click(await screen.findByText('placeholder_warning.send_anyway'));
+    fireEvent.click(await screen.findByText('forgot_attachment.back'));
+    await waitFor(() => expect(screen.queryByText('forgot_attachment.title')).not.toBeInTheDocument());
+
+    fireEvent.change(screen.getByDisplayValue('Lunch'), { target: { value: 'Lunch with {{name}}' } });
+    fireEvent.click(sendButton());
+
+    const dialog = await screen.findByRole('alertdialog');
+    expect(within(dialog).getByText('placeholder_warning.title')).toBeInTheDocument();
+    expect(within(dialog).getByText('{{name}}')).toBeInTheDocument();
+    expect(onSend).not.toHaveBeenCalled();
+  });
+
+  it('ignores placeholders in quoted text and in the signature', async () => {
+    const onSend = vi.fn();
+    const body = '<p>Thanks!</p>'
+      + '<div data-signature-block-node="">[COMPANY]</div>'
+      + '<blockquote><p>Meet at [TIME]? TODO</p></blockquote>';
+    render(<EmailComposer initialData={{ ...DRAFT_WITH_PLACEHOLDER, body }} onSend={onSend} />);
+
+    fireEvent.click(sendButton());
+
+    await waitFor(() => expect(onSend).toHaveBeenCalledTimes(1));
+    expect(screen.queryByText('placeholder_warning.title')).not.toBeInTheDocument();
+  });
+
+  it('sends without asking when the warning is off', async () => {
+    useSettingsStore.setState({ placeholderWarningEnabled: false } as never);
+    const onSend = vi.fn();
+    render(<EmailComposer initialData={DRAFT_WITH_PLACEHOLDER} onSend={onSend} />);
+
+    fireEvent.click(sendButton());
+
+    await waitFor(() => expect(onSend).toHaveBeenCalledTimes(1));
+    expect(screen.queryByText('placeholder_warning.title')).not.toBeInTheDocument();
+  });
+});
diff --git a/components/email/email-composer.tsx b/components/email/email-composer.tsx
index 81495cf59..1b538ec45 100644
--- a/components/email/email-composer.tsx
+++ b/components/email/email-composer.tsx
@@ -89,6 +89,7 @@ import { usePluginSignature } from "@/hooks/use-plugin-signature";
 import { SubAddressHelper } from "@/components/identity/sub-address-helper";
 import { generateSubAddress } from "@/lib/sub-addressing";
 import { substitutePlaceholders, spliceTemplateAboveSignature, composeBodyHasUserContent } from "@/lib/template-utils";
+import { findUnfilledPlaceholders, stripEmbeddedSignatureHtml } from "@/lib/placeholder-check";
 import { TemplatePicker } from "@/components/templates/template-picker";
 import { TemplateForm } from "@/components/templates/template-form";
 import type { EmailTemplate } from "@/lib/template-types";
@@ -478,6 +479,7 @@ export function EmailComposer({
   const attachmentReminderEnabled = useSettingsStore((state) => state.attachmentReminderEnabled);
   const attachmentReminderKeywords = useSettingsStore((state) => state.attachmentReminderKeywords);
   const emptySubjectWarningEnabled = useSettingsStore((state) => state.emptySubjectWarningEnabled);
+  const placeholderWarningEnabled = useSettingsStore((state) => state.placeholderWarningEnabled);
   const recipientMentionsEnabled = useSettingsStore((state) => state.recipientMentionsEnabled);
   const mentionAddsRecipientTo = useSettingsStore((state) => state.mentionAddsRecipientTo);
   const updateSetting = useSettingsStore((state) => state.updateSetting);
@@ -966,6 +968,10 @@ export function EmailComposer({
   const [showEmptySubjectWarning, setShowEmptySubjectWarning] = useState(false);
   const [emptySubjectDelayedUntil, setEmptySubjectDelayedUntil] = useState<string | undefined>();
   const [emptySubjectDontAskAgain, setEmptySubjectDontAskAgain] = useState(false);
+  const [showPlaceholderWarning, setShowPlaceholderWarning] = useState(false);
+  const [placeholderWarningMatches, setPlaceholderWarningMatches] = useState<string[]>([]);
+  const [placeholderWarningDelayedUntil, setPlaceholderWarningDelayedUntil] = useState<string | undefined>();
+  const [placeholderDontAskAgain, setPlaceholderDontAskAgain] = useState(false);
   const [showScheduleDialog, setShowScheduleDialog] = useState(false);
   const [scheduleValue, setScheduleValue] = useState('');
   const [scheduleError, setScheduleError] = useState('');
@@ -997,6 +1003,12 @@ export function EmailComposer({
     restoreFocus: true,
   });
 
+  const placeholderWarningRef = useFocusTrap({
+    isActive: showPlaceholderWarning,
+    onEscape: () => setShowPlaceholderWarning(false),
+    restoreFocus: true,
+  });
+
   const { client: activeClient } = useAuthStore();
   const composerOwnClientRef = useRef(activeClient);
   if (onComposerAccount && activeClient) composerOwnClientRef.current = activeClient;
@@ -3093,6 +3105,9 @@ export function EmailComposer({
   const sendCancelledRef = useRef(false);
   // The user confirmed sending without a subject for this message.
   const emptySubjectConfirmedRef = useRef(false);
+  // Placeholders the user chose to send as they are. The warning comes back
+  // only for one that is not in here.
+  const confirmedPlaceholdersRef = useRef<Set<string>>(new Set());
 
   // Toasts sit in the bottom corner, right over the composer's Send button.
   // The attribute lifts them clear while a composer is open (see toast.tsx).
@@ -3107,6 +3122,41 @@ export function EmailComposer({
     };
   }, []);
 
+  // "Back to editing" from the placeholder warning selects the first
+  // placeholder, so the user can type over it.
+  const selectPlaceholder = (placeholder: string) => {
+    const subjectInput = subjectInputRef.current;
+    const subjectIndex = subjectInput?.value.indexOf(placeholder) ?? -1;
+    if (subjectInput && subjectIndex >= 0) {
+      subjectInput.focus();
+      subjectInput.setSelectionRange(subjectIndex, subjectIndex + placeholder.length);
+      return;
+    }
+    if (plainTextModeRef.current) {
+      const textarea = bodyRef.current;
+      if (!textarea) return;
+      const index = textarea.value.indexOf(placeholder);
+      textarea.focus();
+      if (index >= 0) textarea.setSelectionRange(index, index + placeholder.length);
+      return;
+    }
+    const editor = editorRef.current;
+    if (!editor) return;
+    const range = { from: -1, to: -1 };
+    editor.state.doc.descendants((node, pos) => {
+      if (range.from >= 0) return false;
+      const index = node.isText && node.text ? node.text.indexOf(placeholder) : -1;
+      if (index >= 0) {
+        range.from = pos + index;
+        range.to = range.from + placeholder.length;
+      }
+    });
+    // A placeholder split across formatting has no single text node; then
+    // the caret just goes back into the body.
+    if (range.from >= 0) editor.chain().focus().setTextSelection(range).scrollIntoView().run();
+    else editor.commands.focus();
+  };
+
   const handleSend = async ({ skipAttachmentCheck = false, skipSubjectCheck = false, delayedUntil }: {
     skipAttachmentCheck?: boolean;
     skipSubjectCheck?: boolean;
@@ -3176,6 +3226,27 @@ export function EmailComposer({
       return;
     }
 
+    // Unfilled placeholders: template fields left as {{name}}, fill-ins like
+    // [TIME] from AI drafts, and markers like TODO. The signature is left
+    // out, or a placeholder in it would stop every message.
+    if (placeholderWarningEnabled) {
+      const authored = plainTextMode
+        ? plainTextBodyWithoutSignature(body, signatureIdentity)
+        : stripEmbeddedSignatureHtml(body);
+      const bodyText = extractUserAuthoredText(authored, {
+        plainTextMode,
+        forwardedSeparator: tQuote('forwarded_separator'),
+      });
+      const found = findUnfilledPlaceholders(subject, bodyText);
+      if (found.some(p => !confirmedPlaceholdersRef.current.has(p))) {
+        setPlaceholderWarningMatches(found);
+        setPlaceholderDontAskAgain(false);
+        setPlaceholderWarningDelayedUntil(delayedUntil);
+        setShowPlaceholderWarning(true);
+        return;
+      }
+    }
+
     // Attachment reminder check
     if (!skipAttachmentCheck && attachmentReminderEnabled) {
       const hasAttachments = attachmentsRef.current.some(att => att.blobId && !att.uploading && !att.error);
@@ -3688,6 +3759,7 @@ export function EmailComposer({
       showScheduleDialog ||
       showAttachmentWarning ||
       showEmptySubjectWarning ||
+      showPlaceholderWarning ||
       showCloseDialog
     ) return;
 
@@ -4824,6 +4896,72 @@ export function EmailComposer({
         </div>
       )}
 
+      {showPlaceholderWarning && (
+        <div
+          className="fixed inset-0 bg-black/50 backdrop-blur-[1px] flex items-center justify-center z-[60] p-4 animate-in fade-in duration-150"
+          onClick={() => setShowPlaceholderWarning(false)}
+        >
+          <div
+            ref={placeholderWarningRef}
+            role="alertdialog"
+            aria-modal="true"
+            aria-labelledby="placeholder-warning-title"
+            onClick={(e) => e.stopPropagation()}
+            className="bg-background border border-border rounded-lg shadow-xl w-full max-w-md animate-in zoom-in-95 duration-200"
+          >
+            <div className="p-6">
+              <h2 id="placeholder-warning-title" className="text-lg font-semibold text-foreground">{t('placeholder_warning.title')}</h2>
+              <p className="mt-2 text-sm text-muted-foreground">{t('placeholder_warning.message')}</p>
+              <ul className="mt-3 flex flex-wrap items-center gap-1.5" aria-label={t('placeholder_warning.found')}>
+                {placeholderWarningMatches.slice(0, 5).map((p) => (
+                  <li key={p} className="max-w-full truncate rounded bg-muted px-2 py-0.5 font-mono text-xs text-foreground">{p}</li>
+                ))}
+                {placeholderWarningMatches.length > 5 && (
+                  <li className="text-xs text-muted-foreground">
+                    {t('placeholder_warning.more', { count: placeholderWarningMatches.length - 5 })}
+                  </li>
+                )}
+              </ul>
+              <label className="mt-4 flex items-center gap-2 text-sm text-muted-foreground cursor-pointer">
+                <input
+                  type="checkbox"
+                  checked={placeholderDontAskAgain}
+                  onChange={(e) => setPlaceholderDontAskAgain(e.target.checked)}
+                  className="rounded border-input"
+                />
+                {t('placeholder_warning.dont_ask_again')}
+              </label>
+            </div>
+            <div className="flex items-center justify-end gap-3 px-6 pb-6">
+              <Button
+                variant="outline"
+                onClick={() => {
+                  setShowPlaceholderWarning(false);
+                  setPlaceholderWarningDelayedUntil(undefined);
+                  // The focus trap hands focus back to the Send button as it
+                  // tears down, so select on the next tick.
+                  const first = placeholderWarningMatches[0];
+                  setTimeout(() => { if (first) selectPlaceholder(first); }, 0);
+                }}
+              >
+                {t('placeholder_warning.back')}
+              </Button>
+              <Button
+                onClick={() => {
+                  if (placeholderDontAskAgain) updateSetting('placeholderWarningEnabled', false);
+                  placeholderWarningMatches.forEach((p) => confirmedPlaceholdersRef.current.add(p));
+                  setShowPlaceholderWarning(false);
+                  handleSend({ skipSubjectCheck: true, delayedUntil: placeholderWarningDelayedUntil });
+                  setPlaceholderWarningDelayedUntil(undefined);
+                }}
+              >
+                {t('placeholder_warning.send_anyway')}
+              </Button>
+            </div>
+          </div>
+        </div>
+      )}
+
       {showCloseDialog && (
         <div
           className="fixed inset-0 bg-black/50 backdrop-blur-[1px] flex items-center justify-center z-[60] p-4 animate-in fade-in duration-150"
diff --git a/locales/en/common.json b/locales/en/common.json
index 18fdfc338..6f7d938dd 100644
--- a/locales/en/common.json
+++ b/locales/en/common.json
@@ -803,6 +803,15 @@
       "send_anyway": "Send anyway",
       "back": "Back to editing"
     },
+    "placeholder_warning": {
+      "title": "Check placeholders?",
+      "message": "Your message has placeholder text that recipients will see. Do you want to edit it before sending?",
+      "found": "Placeholders found",
+      "more": "and {count} more",
+      "dont_ask_again": "Don't ask again",
+      "send_anyway": "Send anyway",
+      "back": "Back to editing"
+    },
     "schedule_send": "Schedule send",
     "schedule_send_description": "Choose when the server should release this message.",
     "schedule_preset": {
diff --git a/stores/settings-store.ts b/stores/settings-store.ts
index c1fafd300..bf50b3338 100644
--- a/stores/settings-store.ts
+++ b/stores/settings-store.ts
@@ -682,6 +682,9 @@ interface SettingsState {
   // Ask for confirmation when sending a message with an empty subject
   emptySubjectWarningEnabled: boolean;
 
+  // Ask for confirmation when sending a message with unfilled placeholders
+  placeholderWarningEnabled: boolean;
+
   // "@" in the message body offers the recipients and inserts a first name
   recipientMentionsEnabled: boolean;
   // Where an "@" puts a picked contact who isn't a recipient yet; 'off'
@@ -975,6 +978,7 @@ const DEFAULT_SETTINGS = {
   ] as string[],
 
   emptySubjectWarningEnabled: true,
+  placeholderWarningEnabled: true,
   recipientMentionsEnabled: true,
   mentionAddsRecipientTo: 'to' as MentionAddsRecipientTo,
 
@@ -1275,6 +1279,7 @@ export const useSettingsStore = create<SettingsState>()(
           attachmentReminderEnabled: state.attachmentReminderEnabled,
           attachmentReminderKeywords: state.attachmentReminderKeywords,
           emptySubjectWarningEnabled: state.emptySubjectWarningEnabled,
+          placeholderWarningEnabled: state.placeholderWarningEnabled,
           recipientMentionsEnabled: state.recipientMentionsEnabled,
           mentionAddsRecipientTo: state.mentionAddsRecipientTo,
           hideInlineImageAttachments: state.hideInlineImageAttachments,