diff --git a/components/email/email-viewer.tsx b/components/email/email-viewer.tsx
index ca98cffd..88ff7781 100644
--- a/components/email/email-viewer.tsx
+++ b/components/email/email-viewer.tsx
@@ -809,6 +809,15 @@ export function EmailViewer({
   const [pluginRenderedHtml, setPluginRenderedHtml] = useState<string | null>(null);
   const [pluginRenderedText, setPluginRenderedText] = useState<string | null>(null);
   const [pluginRenderedAttachments, setPluginRenderedAttachments] = useState<PostalMimeAttachment[]>([]);
+  // Bumped when a plugin calls `api.ui.rerenderEmail` (e.g. the S/MIME plugin
+  // after the user unlocks a key from the banner) to force the onRenderEmailBody
+  // hook to run again for the open message so the body re-decrypts.
+  const [pluginRenderNonce, setPluginRenderNonce] = useState(0);
+  useEffect(() => {
+    const bump = () => setPluginRenderNonce((n) => n + 1);
+    window.addEventListener('plugin:rerender-email', bump);
+    return () => window.removeEventListener('plugin:rerender-email', bump);
+  }, []);
 
   // TNEF (winmail.dat) support
   const [tnefHtml, setTnefHtml] = useState<string | null>(null);
@@ -1205,7 +1214,7 @@ export function EmailViewer({
     })();
 
     return () => { cancelled = true; };
-  }, [email]);
+  }, [email, pluginRenderNonce]);
 
   // TNEF (winmail.dat) detection and processing
   useEffect(() => {
diff --git a/components/email/read-receipt-banner.tsx b/components/email/read-receipt-banner.tsx
index ff4acc4a..dfaff891 100644
--- a/components/email/read-receipt-banner.tsx
+++ b/components/email/read-receipt-banner.tsx
@@ -1,7 +1,7 @@
 'use client';
 
 import { useState } from 'react';
-import { MailCheck, Loader2, CheckCircle } from 'lucide-react';
+import { MailCheck, Loader2, CheckCircle, X } from 'lucide-react';
 import { useTranslations } from 'next-intl';
 
 interface ReadReceiptBannerProps {
@@ -17,43 +17,61 @@ export function ReadReceiptBanner({ requestedBy, onSend, onIgnore }: ReadReceipt
   const t = useTranslations('email_viewer.read_receipt');
   const [state, setState] = useState<'idle' | 'sending' | 'sent'>('idle');
 
+  // Matches the host's "External Content" banner row: a round tinted icon chip,
+  // an uppercase eyebrow, a foreground message, and neutral bordered actions.
   if (state === 'sent') {
     return (
-      <div className="flex items-center gap-2 rounded-md border border-border bg-muted/40 px-3 py-2 text-sm text-muted-foreground">
-        <CheckCircle className="w-4 h-4 text-green-600 dark:text-green-400 shrink-0" />
-        <span>{t('sent')}</span>
+      <div className="flex items-center gap-3 py-1">
+        <div className="w-10 h-10 rounded-full bg-success/15 text-success flex items-center justify-center flex-shrink-0 shadow-sm">
+          <CheckCircle className="w-5 h-5" />
+        </div>
+        <span className="text-sm text-muted-foreground">{t('sent')}</span>
       </div>
     );
   }
 
   return (
-    <div className="flex flex-wrap items-center gap-2 rounded-md border border-amber-300/60 bg-amber-50 px-3 py-2 text-sm dark:border-amber-700/50 dark:bg-amber-950/30">
-      <MailCheck className="w-4 h-4 shrink-0 text-amber-600 dark:text-amber-400" />
-      <span className="text-foreground">{t('prompt')}</span>
-      <span className="break-all text-muted-foreground">{requestedBy}</span>
-      <div className="ms-auto flex items-center gap-2">
-        <button
-          onClick={async () => {
-            setState('sending');
-            try {
-              await onSend();
-              setState('sent');
-            } catch {
-              setState('idle');
-            }
-          }}
-          disabled={state === 'sending'}
-          className="inline-flex items-center gap-1.5 rounded-md bg-green-600 px-3 py-1.5 text-xs font-medium text-white transition-colors hover:bg-green-700 disabled:cursor-not-allowed disabled:opacity-50"
-        >
-          {state === 'sending' && <Loader2 className="w-3 h-3 animate-spin" />}
-          {t('send')}
-        </button>
-        <button
-          onClick={onIgnore}
-          className="rounded-md bg-red-600 px-3 py-1.5 text-xs font-medium text-white transition-colors hover:bg-red-700"
-        >
-          {t('ignore')}
-        </button>
+    <div className="flex items-start gap-3 py-1">
+      <div className="w-10 h-10 rounded-full bg-info/15 text-info flex items-center justify-center flex-shrink-0 shadow-sm">
+        <MailCheck className="w-5 h-5" />
+      </div>
+      <div className="flex-1 min-w-0 space-y-2">
+        <div>
+          <div className="text-[10px] font-semibold uppercase tracking-wider text-muted-foreground">
+            Read receipt
+          </div>
+          <div className="text-sm font-medium text-foreground break-words">
+            {t('prompt')}
+          </div>
+          <div className="text-xs text-muted-foreground break-all">
+            Requested by <span className="text-foreground/80">{requestedBy}</span>
+          </div>
+        </div>
+        <div className="flex flex-wrap items-center gap-1.5 pt-0.5">
+          <button
+            onClick={async () => {
+              setState('sending');
+              try {
+                await onSend();
+                setState('sent');
+              } catch {
+                setState('idle');
+              }
+            }}
+            disabled={state === 'sending'}
+            className="inline-flex items-center gap-1.5 text-sm text-muted-foreground hover:text-foreground px-3 py-1.5 rounded-md border border-border hover:bg-muted transition-colors min-h-[36px] disabled:opacity-50 disabled:cursor-not-allowed"
+          >
+            {state === 'sending' ? <Loader2 className="w-3.5 h-3.5 animate-spin" /> : <MailCheck className="w-3.5 h-3.5" />}
+            {t('send')}
+          </button>
+          <button
+            onClick={onIgnore}
+            className="inline-flex items-center gap-1.5 text-sm text-muted-foreground hover:text-foreground px-3 py-1.5 rounded-md border border-border hover:bg-muted transition-colors min-h-[36px]"
+          >
+            <X className="w-3.5 h-3.5" />
+            {t('ignore')}
+          </button>
+        </div>
       </div>
     </div>
   );
diff --git a/lib/plugin-sandbox/host-api.ts b/lib/plugin-sandbox/host-api.ts
index 1a983616..6bcd2870 100644
--- a/lib/plugin-sandbox/host-api.ts
+++ b/lib/plugin-sandbox/host-api.ts
@@ -56,6 +56,7 @@ const PERM_PER_METHOD: Record<string, Permission | null> = {
   'ui.confirm': null,
   'ui.alert': null,
   'ui.prompt': null,
+  'ui.rerenderEmail': null,
   'ui.openExternalUrl': null,
 };
 
@@ -410,6 +411,14 @@ export async function dispatchApiCall(
         fields,
       });
     }
+    case 'ui.rerenderEmail': {
+      // Re-run the onRenderEmailBody hook for the currently open message. Used
+      // by crypto plugins after they change decryption state (e.g. an S/MIME key
+      // was just unlocked) so the body re-decrypts without a full reload — which
+      // would wipe the in-memory session keys.
+      window.dispatchEvent(new CustomEvent('plugin:rerender-email'));
+      return undefined;
+    }
     case 'ui.openExternalUrl': {
       const url = String(args[0] ?? '');
       // Only http(s) - the sandbox should not be able to navigate the host
diff --git a/lib/plugin-sandbox/protocol.ts b/lib/plugin-sandbox/protocol.ts
index 9385aa76..fe61555f 100644
--- a/lib/plugin-sandbox/protocol.ts
+++ b/lib/plugin-sandbox/protocol.ts
@@ -244,7 +244,7 @@ export const API_METHODS = [
   'jmap.fetchBlob', 'jmap.sendRaw',
   'admin.getConfig', 'admin.getAllConfig', 'admin.setConfig', 'admin.deleteConfig',
   'toast.success', 'toast.error', 'toast.info', 'toast.warning',
-  'ui.confirm', 'ui.alert', 'ui.prompt', 'ui.openExternalUrl',
+  'ui.confirm', 'ui.alert', 'ui.prompt', 'ui.rerenderEmail', 'ui.openExternalUrl',
 ] as const;
 
 export type ApiMethod = (typeof API_METHODS)[number];
diff --git a/lib/plugin-sandbox/runtime.tsx b/lib/plugin-sandbox/runtime.tsx
index 03f37692..fa9343e5 100644
--- a/lib/plugin-sandbox/runtime.tsx
+++ b/lib/plugin-sandbox/runtime.tsx
@@ -223,6 +223,9 @@ function buildPluginApi(manifest: PluginManifest) {
         cancelLabel?: string;
         fields?: Array<{ name: string; label: string; type?: 'text' | 'password'; placeholder?: string; required?: boolean }>;
       }) => callApi('ui.prompt', [opts], 0) as Promise<Record<string, string> | null>,
+      /** Re-runs the onRenderEmailBody hook for the open message (e.g. after a
+       *  crypto plugin unlocks a key) so its body re-renders without a reload. */
+      rerenderEmail: () => callApi('ui.rerenderEmail', []) as Promise<void>,
       /** Opens an http/https URL in a new tab via host `window.open`. */
       openExternalUrl: (url: string, target?: string) =>
         callApi('ui.openExternalUrl', [url, target]) as Promise<void>,
diff --git a/locales/en/common.json b/locales/en/common.json
index 324bdf18..7de12348 100644
--- a/locales/en/common.json
+++ b/locales/en/common.json
@@ -257,7 +257,7 @@
   },
   "email_viewer": {
     "read_receipt": {
-      "prompt": "The sender requested a read receipt:",
+      "prompt": "The sender asked to be notified when you open this message.",
       "send": "Send receipt",
       "ignore": "Ignore",
       "sent": "Read receipt sent.",