diff --git a/app/[locale]/page.tsx b/app/[locale]/page.tsx
index d4c90318..c0de511b 100644
--- a/app/[locale]/page.tsx
+++ b/app/[locale]/page.tsx
@@ -60,25 +60,7 @@ import { useConfig } from "@/hooks/use-config";
 import { usePluginStore } from "@/stores/plugin-store";
 import { useThemeStore } from "@/stores/theme-store";
 import { appLifecycleHooks, uiHooks, routerHooks, toastHooks, emailHooks } from "@/lib/plugin-hooks";
-import type { EmailReadView } from "@/lib/plugin-types";
-
-function emailToReadView(email: Email): EmailReadView {
-  return {
-    id: email.id,
-    threadId: email.threadId,
-    mailboxIds: Object.keys(email.mailboxIds || {}).filter(k => email.mailboxIds[k]),
-    from: (email.from || []).map(a => ({ name: a.name || '', email: a.email })),
-    to: (email.to || []).map(a => ({ name: a.name || '', email: a.email })),
-    cc: (email.cc || []).map(a => ({ name: a.name || '', email: a.email })),
-    subject: email.subject || '',
-    receivedAt: email.receivedAt,
-    isRead: !!email.keywords?.['$seen'],
-    isFlagged: !!email.keywords?.['$flagged'],
-    hasAttachment: email.hasAttachment,
-    preview: email.preview || '',
-    keywords: Object.keys(email.keywords || {}).filter(k => email.keywords[k]),
-  };
-}
+import { emailToReadView } from "@/lib/plugin-projection";
 
 
 export default function Home() {
diff --git a/components/email/email-viewer.tsx b/components/email/email-viewer.tsx
index f92b435a..b37f5abe 100644
--- a/components/email/email-viewer.tsx
+++ b/components/email/email-viewer.tsx
@@ -9,6 +9,7 @@ import { Button } from "@/components/ui/button";
 import { Avatar } from "@/components/ui/avatar";
 import { formatFileSize, cn, buildMailboxTree, MailboxNode, formatDateTime, generateUUID } from "@/lib/utils";
 import { getSecurityStatus, extractListHeaders } from "@/lib/email-headers";
+import { emailToReadView } from "@/lib/plugin-projection";
 import {
   Reply,
   ReplyAll,
@@ -4886,7 +4887,7 @@ export function EmailViewer({
 
         <div>
 
-          <PluginSlot name="email-banner" extraProps={{ email }} />
+          <PluginSlot name="email-banner" extraProps={{ email: emailToReadView(email) }} />
 
           {/* Email Body */}
           <div className={cn(
diff --git a/lib/plugin-projection.ts b/lib/plugin-projection.ts
new file mode 100644
index 00000000..465d7693
--- /dev/null
+++ b/lib/plugin-projection.ts
@@ -0,0 +1,25 @@
+// Projection helpers — convert host-internal types into the read-only views
+// that plugins consume. Keeping this in one place ensures every slot/hook
+// hands plugins the same shape declared in plugin-types.ts.
+
+import type { Email } from '@/lib/jmap/types';
+import type { EmailReadView } from '@/lib/plugin-types';
+
+export function emailToReadView(email: Email): EmailReadView {
+  return {
+    id: email.id,
+    threadId: email.threadId,
+    mailboxIds: Object.keys(email.mailboxIds || {}).filter(k => email.mailboxIds[k]),
+    from: (email.from || []).map(a => ({ name: a.name || '', email: a.email })),
+    to: (email.to || []).map(a => ({ name: a.name || '', email: a.email })),
+    cc: (email.cc || []).map(a => ({ name: a.name || '', email: a.email })),
+    subject: email.subject || '',
+    receivedAt: email.receivedAt,
+    isRead: !!email.keywords?.['$seen'],
+    isFlagged: !!email.keywords?.['$flagged'],
+    hasAttachment: email.hasAttachment,
+    preview: email.preview || '',
+    keywords: Object.keys(email.keywords || {}).filter(k => email.keywords[k]),
+    auth: email.authenticationResults,
+  };
+}
diff --git a/lib/plugin-types.ts b/lib/plugin-types.ts
index 995d1e78..780ec021 100644
--- a/lib/plugin-types.ts
+++ b/lib/plugin-types.ts
@@ -300,6 +300,17 @@ export interface EmailReadView {
   hasAttachment: boolean;
   preview: string;
   keywords: string[];
+  /**
+   * Parsed Authentication-Results header (SPF, DKIM, DMARC, reverse-DNS).
+   * Absent on stores that didn't parse the header (e.g. bodies not yet
+   * fetched). Mirrors the structured shape exposed by the host.
+   */
+  auth?: {
+    spf?: { result: 'pass' | 'fail' | 'softfail' | 'neutral' | 'none' | 'temperror' | 'permerror'; domain?: string };
+    dkim?: { result: 'pass' | 'fail' | 'policy' | 'neutral' | 'temperror' | 'permerror'; domain?: string; selector?: string };
+    dmarc?: { result: 'pass' | 'fail' | 'none'; policy?: 'reject' | 'quarantine' | 'none'; domain?: string };
+    iprev?: { result: 'pass' | 'fail'; ip?: string };
+  };
 }
 
 export interface DraftView {