diff --git a/app/(main)/[locale]/pro/page.tsx b/app/(main)/[locale]/pro/page.tsx
index e709100e4..6c6cc861c 100644
--- a/app/(main)/[locale]/pro/page.tsx
+++ b/app/(main)/[locale]/pro/page.tsx
@@ -12,6 +12,7 @@ import { useEmailStore } from "@/stores/email-store";
 import { useSettingsStore } from "@/stores/settings-store";
 import { useDeviceDetection } from "@/hooks/use-media-query";
 import { EmbeddedContext } from "@/hooks/use-is-embedded";
+import { OrgAnnouncement } from "@/components/org/org-announcement";
 import { PaneSizeContext } from "@/hooks/use-pane-size";
 import { PaneIdContext, ProTabFocusContext } from "@/hooks/use-pane-context";
 import { useDeepLinkUrl } from "@/hooks/use-deep-link-url";
@@ -511,6 +512,8 @@ export default function ProHome() {
   return (
     <EmbeddedContext.Provider value={true}>
       <div className="flex flex-col h-dvh bg-background overflow-hidden pt-[env(safe-area-inset-top)]">
+        {/* Once for the whole shell: email and folder tabs have no app strip, and split panes would show it twice. */}
+        <OrgAnnouncement />
         <div className="flex flex-1 overflow-hidden">
           {/* Leftmost Navigation Rail - identical to the standard layout */}
           <div
diff --git a/components/admin/org/sections/announcement-section.tsx b/components/admin/org/sections/announcement-section.tsx
index 949798e8a..ea4a500a4 100644
--- a/components/admin/org/sections/announcement-section.tsx
+++ b/components/admin/org/sections/announcement-section.tsx
@@ -280,7 +280,7 @@ export function AnnouncementSection({ draft }: { draft: OrgPolicyDraft }) {
             {!badRange && ended && <p className="text-xs text-amber-700 dark:text-amber-300">The end time has passed, so nobody sees it.</p>}
             <p className="text-xs text-muted-foreground">Times are in your browser&apos;s time zone. Open tabs show and hide the announcement on time without a reload.</p>
 
-            <SettingItem label="Users can close it" description="Closed stays closed for that account in that browser until you change the announcement. Turn this off for messages everyone must see.">
+            <SettingItem label="Users can close it" description="Closed stays closed for that account in that browser until you change its text or severity; moving the start or end doesn't show it again. Turn this off for messages everyone must see.">
               <ToggleSwitch checked={announcement.dismissible} onChange={(v) => set({ dismissible: v })} testId="org-announcement-dismissible" />
             </SettingItem>
 
diff --git a/components/org/__tests__/org-announcement.test.tsx b/components/org/__tests__/org-announcement.test.tsx
index 7e1b41bc1..0ff9a8f1e 100644
--- a/components/org/__tests__/org-announcement.test.tsx
+++ b/components/org/__tests__/org-announcement.test.tsx
@@ -40,12 +40,18 @@ describe('OrgAnnouncement', () => {
     expect(screen.queryByTestId('org-announcement')).toBeNull();
   });
 
-  it('shows the text with the critical role for a critical announcement', () => {
+  it('shows the text, and reads a critical one out as an alert after it is in the page', () => {
+    vi.useFakeTimers({ toFake: ['setTimeout', 'clearTimeout'] });
     setAnnouncement({ severity: 'critical' });
     render(<OrgAnnouncement />);
     const banner = screen.getByTestId('org-announcement');
     expect(banner.textContent).toContain('Mail is down tonight');
-    expect(banner.getAttribute('role')).toBe('alert');
+    const live = screen.getByTestId('org-announcement-live');
+    expect(live.getAttribute('role')).toBe('alert');
+    // Empty when it appears, filled a moment later: only a change is announced.
+    expect(live.textContent).toBe('');
+    act(() => { vi.advanceTimersByTime(200); });
+    expect(live.textContent).toBe('severity_critical: Mail is down tonight');
   });
 
   it('goes away at its end time without a reload', () => {
@@ -58,6 +64,18 @@ describe('OrgAnnouncement', () => {
     expect(screen.queryByTestId('org-announcement')).toBeNull();
   });
 
+  it('shows one that arrives with a refetch after its start, in a tab open since before', () => {
+    vi.useFakeTimers({ toFake: ['setTimeout', 'clearTimeout', 'Date'] });
+    vi.setSystemTime(new Date('2026-11-02T08:00:00Z'));
+    usePolicyStore.setState({ policy: { ...DEFAULT_POLICY } });
+    render(<OrgAnnouncement />);
+    expect(screen.queryByTestId('org-announcement')).toBeNull();
+    // Two hours later a refetch brings an announcement that started at 09:00.
+    vi.setSystemTime(new Date('2026-11-02T10:05:00Z'));
+    act(() => setAnnouncement({ id: 'n-late', startsAt: '2026-11-02T09:00:00.000Z', endsAt: '2026-11-02T12:00:00.000Z' }));
+    expect(screen.getByTestId('org-announcement')).toBeTruthy();
+  });
+
   it('appears at its start time without a reload', () => {
     vi.useFakeTimers({ toFake: ['setTimeout', 'clearTimeout', 'Date'] });
     vi.setSystemTime(new Date('2026-11-02T07:59:00Z'));
@@ -100,9 +118,10 @@ describe('OrgAnnouncement', () => {
   it('is read out once per page load, then is a plain region', () => {
     setAnnouncement({ id: 'n-once' });
     const { unmount } = render(<OrgAnnouncement />);
-    expect(screen.getByTestId('org-announcement').getAttribute('role')).toBe('status');
+    expect(screen.getByTestId('org-announcement').getAttribute('role')).toBe('region');
+    expect(screen.getByTestId('org-announcement-live').getAttribute('role')).toBe('status');
     unmount();
     render(<OrgAnnouncement />);
-    expect(screen.getByTestId('org-announcement').getAttribute('role')).toBe('region');
+    expect(screen.queryByTestId('org-announcement-live')).toBeNull();
   });
 });
diff --git a/components/org/org-announcement.tsx b/components/org/org-announcement.tsx
index 286f0c123..2c7933013 100644
--- a/components/org/org-announcement.tsx
+++ b/components/org/org-announcement.tsx
@@ -36,16 +36,40 @@ const STYLES = {
 
 const ICONS = { info: Info, warning: AlertTriangle, critical: AlertCircle } as const;
 
-/** Re-renders when the announcement starts or ends. */
-function useNow(change: number | null): number {
-  const [now, setNow] = useState(() => Date.now());
+/**
+ * The time now, read on every render (an announcement that arrives with a
+ * policy refetch is judged by the real time), plus a re-render when the
+ * announcement starts or ends.
+ */
+function useClock(change: number | null): number {
+  const [tick, setTick] = useState(0);
   useEffect(() => {
     if (change === null) return;
     const wait = Math.min(MAX_TIMER_MS, Math.max(0, change - Date.now()) + 50);
-    const timer = setTimeout(() => setNow(Date.now()), wait);
+    const timer = setTimeout(() => setTick((n) => n + 1), wait);
     return () => clearTimeout(timer);
-  }, [change, now]);
-  return now;
+  }, [change, tick]);
+  return Date.now();
+}
+
+/**
+ * Reads the announcement out once: a live region that is in the page empty
+ * and gets the text a moment later (text already there when a live region
+ * appears isn't announced reliably), then empties again so browsing the
+ * page doesn't meet it twice.
+ */
+function LiveOnce({ text, assertive }: { text: string; assertive: boolean }) {
+  const [said, setSaid] = useState('');
+  useEffect(() => {
+    const fill = setTimeout(() => setSaid(text), 150);
+    const clear = setTimeout(() => setSaid(''), 15_000);
+    return () => { clearTimeout(fill); clearTimeout(clear); };
+  }, [text]);
+  return (
+    <div role={assertive ? 'alert' : 'status'} className="sr-only" data-testid="org-announcement-live">
+      {said}
+    </div>
+  );
 }
 
 function openLink(event: MouseEvent<HTMLAnchorElement>, href: string) {
@@ -71,7 +95,7 @@ export function OrgAnnouncement() {
   const [dismissedKey, setDismissedKey] = useState<string | null>(null);
 
   const text = announcement ? announcementText(announcement, locale) : '';
-  const now = useNow(text ? nextAnnouncementChange(announcement, Date.now()) : null);
+  const now = useClock(text ? nextAnnouncementChange(announcement, Date.now()) : null);
   const key = announcement && text ? announcementKey(announcement) : null;
   const active = !!key && announcementActive(announcement, now);
   const dismissed = !!key && !!announcement?.dismissible
@@ -87,19 +111,20 @@ export function OrgAnnouncement() {
   if (!visible || !announcement) return null;
   const severity = announcement.severity in STYLES ? announcement.severity : 'info';
   const Icon = ICONS[severity];
-  const role = firstShow ? (severity === 'critical' ? 'alert' : 'status') : 'region';
+  const severityLabel = t(`severity_${severity}`);
 
   return (
     <div
-      role={role}
-      aria-label={role === 'region' ? t('label') : undefined}
+      role="region"
+      aria-label={t('label')}
       data-testid="org-announcement"
       data-severity={severity}
       className={cn('flex shrink-0 items-start gap-2 border-b px-3 text-sm sm:px-4', STYLES[severity])}
     >
+      {firstShow && <LiveOnce text={`${severityLabel}: ${text}`} assertive={severity === 'critical'} />}
       <Icon className="mt-3 h-4 w-4 shrink-0" aria-hidden="true" />
       <p className="min-w-0 flex-1 whitespace-pre-line break-words py-2.5 leading-snug [overflow-wrap:anywhere]">
-        <span className="sr-only">{t(`severity_${severity}`)}: </span>
+        <span className="sr-only">{severityLabel}: </span>
         {parts.map((part, index) => part.kind === 'link' ? (
           <a
             key={index}
diff --git a/components/plugins/__tests__/app-top-banner-slot.test.tsx b/components/plugins/__tests__/app-top-banner-slot.test.tsx
index 56e131bef..885139320 100644
--- a/components/plugins/__tests__/app-top-banner-slot.test.tsx
+++ b/components/plugins/__tests__/app-top-banner-slot.test.tsx
@@ -14,6 +14,7 @@ vi.mock('@/components/plugins/plugin-slot', () => ({
 }));
 
 import { AppTopBannerSlot } from '@/components/plugins/app-top-banner-slot';
+import { EmbeddedContext } from '@/hooks/use-is-embedded';
 import { useAccountStore } from '@/stores/account-store';
 import { useAuthStore } from '@/stores/auth-store';
 
@@ -46,4 +47,10 @@ describe('AppTopBannerSlot', () => {
     render(<AppTopBannerSlot />);
     expect(screen.getByTestId('org-announcement')).toBeTruthy();
   });
+
+  it('leaves the announcement to the Pro shell, which shows it once for all its panes', () => {
+    useAccountStore.setState({ accounts: [account], activeAccountId: account.id });
+    render(<EmbeddedContext.Provider value={true}><AppTopBannerSlot /></EmbeddedContext.Provider>);
+    expect(screen.queryByTestId('org-announcement')).toBeNull();
+  });
 });
diff --git a/components/plugins/app-top-banner-slot.tsx b/components/plugins/app-top-banner-slot.tsx
index c6de8efff..0115007a8 100644
--- a/components/plugins/app-top-banner-slot.tsx
+++ b/components/plugins/app-top-banner-slot.tsx
@@ -2,6 +2,7 @@
 
 import { PluginSlot } from '@/components/plugins/plugin-slot';
 import { OrgAnnouncement } from '@/components/org/org-announcement';
+import { useIsEmbedded } from '@/hooks/use-is-embedded';
 import { useAccountStore } from '@/stores/account-store';
 import { useAuthStore } from '@/stores/auth-store';
 
@@ -11,17 +12,19 @@ import { useAuthStore } from '@/stores/auth-store';
  * impersonation handoff (`impersonated`). Drop this at the top of every
  * authenticated page so plugins like impersonation-notice render
  * everywhere, not just on the mail page. The organisation's announcement
- * (Organisation > Notices) shows here too, above the plugins' banners.
+ * (Organisation > Notices) shows here too, above the plugins' banners,
+ * except inside the Pro shell, which shows it once across all its panes.
  */
 export function AppTopBannerSlot() {
   const username = useAuthStore((s) => s.username);
   const serverUrl = useAuthStore((s) => s.serverUrl);
+  const embedded = useIsEmbedded();
   const impersonated = useAccountStore(
     (s) => s.accounts.find((a) => a.id === s.activeAccountId)?.impersonated === true,
   );
   return (
     <>
-      <OrgAnnouncement />
+      {!embedded && <OrgAnnouncement />}
       <PluginSlot name="app-top-banner" extraProps={{ username, serverUrl, impersonated }} />
     </>
   );
diff --git a/lib/__tests__/org-announcement.test.ts b/lib/__tests__/org-announcement.test.ts
index 31c74102f..4b7c65ea8 100644
--- a/lib/__tests__/org-announcement.test.ts
+++ b/lib/__tests__/org-announcement.test.ts
@@ -67,13 +67,19 @@ describe('dismissal', () => {
     expect(isAnnouncementDismissed(base, 'acc-2')).toBe(false);
   });
 
-  it('no longer holds once the admin edits the text, or for a new announcement', () => {
+  it('no longer holds once the admin edits the text or severity, or for a new announcement', () => {
     dismissAnnouncement(base, 'acc-1');
     expect(isAnnouncementDismissed({ ...base, text: { ...base.text, en: 'Maintenance moved to Friday' } }, 'acc-1')).toBe(false);
-    expect(isAnnouncementDismissed({ ...base, endsAt: '2026-12-01T00:00:00.000Z' }, 'acc-1')).toBe(false);
+    expect(isAnnouncementDismissed({ ...base, severity: 'critical' }, 'acc-1')).toBe(false);
     expect(isAnnouncementDismissed({ ...base, id: 'a2' }, 'acc-1')).toBe(false);
   });
 
+  it('still holds when only the start or end time moves', () => {
+    dismissAnnouncement(base, 'acc-1');
+    expect(isAnnouncementDismissed({ ...base, endsAt: '2026-12-01T00:00:00.000Z' }, 'acc-1')).toBe(true);
+    expect(isAnnouncementDismissed({ ...base, startsAt: '2026-11-01T00:00:00.000Z' }, 'acc-1')).toBe(true);
+  });
+
   it('does not depend on the order of the languages', () => {
     const reordered = { ...base, text: { 'pt-BR': base.text['pt-BR'], de: base.text.de, en: base.text.en } };
     expect(announcementKey(reordered)).toBe(announcementKey(base));
diff --git a/lib/org-announcement.ts b/lib/org-announcement.ts
index a9cc8f86d..279d1bf94 100644
--- a/lib/org-announcement.ts
+++ b/lib/org-announcement.ts
@@ -63,13 +63,15 @@ export function nextAnnouncementChange(announcement: Announcement | undefined |
   return times.length > 0 ? Math.min(...times) : null;
 }
 
-/** FNV-1a over the content an admin edits: a new text, time or severity is a new announcement for dismissals. */
+/**
+ * FNV-1a over what the message says: a new text or severity is a new
+ * announcement for dismissals. Moving its start or end isn't; whoever
+ * closed it keeps it closed.
+ */
 export function announcementHash(announcement: Announcement): string {
   const content = JSON.stringify([
     Object.entries(announcement.text ?? {}).sort(([a], [b]) => a.localeCompare(b)),
     announcement.severity,
-    announcement.startsAt,
-    announcement.endsAt,
   ]);
   let hash = 0x811c9dc5;
   for (let i = 0; i < content.length; i++) {