diff --git a/src/features/dashboard/components/Greeting.tsx b/src/features/dashboard/components/Greeting.tsx
index 91a7930..3ebfeb6 100644
--- a/src/features/dashboard/components/Greeting.tsx
+++ b/src/features/dashboard/components/Greeting.tsx
@@ -4,8 +4,10 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
+import { useEffect, useState } from 'react';
 import { useTranslation } from 'react-i18next';
 import { useAuthStore } from '@/stores/authStore';
+import { getAccountId, jmapQueryAndGet } from '@/services/jmap/client';
 import inbuxaMark from '@/assets/inbuxa-mark.png';
 
 function partOfDay(hour: number): 'morning' | 'afternoon' | 'evening' {
@@ -14,13 +16,40 @@ function partOfDay(hour: number): 'morning' | 'afternoon' | 'evening' {
   return 'evening';
 }
 
-/** The dashboard's hello: whose server this is, and a nod to the time of day. */
+/**
+ * The name to greet: the account's full name where it has one, otherwise the
+ * name it signs in with. Looked up by the local part and matched on the whole
+ * address, so an account of the same name on another domain can't answer.
+ */
+function useFullName(username: string | null): string | null {
+  const [fullName, setFullName] = useState<string | null>(null);
+  useEffect(() => {
+    if (!username) return;
+    let live = true;
+    const localPart = username.split('@')[0];
+    jmapQueryAndGet('x:Account', getAccountId('x:Account'), { filter: { name: localPart } }, ['description', 'emailAddress'])
+      .then((responses) => {
+        const list = (responses[1]?.[1] as { list?: { description?: string | null; emailAddress?: string }[] }).list ?? [];
+        const own = list.find((a) => a.emailAddress?.toLowerCase() === username.toLowerCase());
+        const name = own?.description?.trim();
+        if (live && name) setFullName(name);
+      })
+      .catch(() => {
+        /* the sign-in name stands */
+      });
+    return () => {
+      live = false;
+    };
+  }, [username]);
+  return fullName;
+}
+
+/** The dashboard's hello: to whoever is signed in, with a nod to the time of day. */
 export function Greeting() {
   const { t } = useTranslation();
-  const accounts = useAuthStore((s) => s.accounts);
-  const activeAccountId = useAuthStore((s) => s.activeAccountId);
-  const full = (activeAccountId && accounts[activeAccountId]?.name) || '';
-  const name = full.split('@')[0];
+  const username = useAuthStore((s) => s.username);
+  const fullName = useFullName(username);
+  const name = fullName ?? username?.split('@')[0] ?? '';
   const part = partOfDay(new Date().getHours());
   const hello =
     part === 'morning'
@@ -36,7 +65,13 @@ export function Greeting() {
           {hello}
           {name && `, ${name}`}
         </h1>
-        <p className="text-sm text-muted-foreground">
+        <p className="truncate text-sm text-muted-foreground">
+          {username && (
+            <>
+              {t('greeting.signedInAs', 'Signed in as {{username}}', { username })}
+              {' · '}
+            </>
+          )}
           {t('greeting.subtitle', "Here's how your mail server is doing.")}
         </p>
       </div>
diff --git a/src/i18n/en.json b/src/i18n/en.json
index bbdf247..be197d3 100644
--- a/src/i18n/en.json
+++ b/src/i18n/en.json
@@ -389,6 +389,7 @@
     "morning": "Good morning",
     "afternoon": "Good afternoon",
     "evening": "Good evening",
-    "subtitle": "Here's how your mail server is doing."
+    "subtitle": "Here's how your mail server is doing.",
+    "signedInAs": "Signed in as {{username}}"
   }
 }
diff --git a/src/pages/AdminPanel.tsx b/src/pages/AdminPanel.tsx
index 7324799..d0dc825 100644
--- a/src/pages/AdminPanel.tsx
+++ b/src/pages/AdminPanel.tsx
@@ -143,6 +143,7 @@ export default function AdminPanel() {
 
         if (cancelled) return;
         setSession(accounts, primaryAccountId, apiUrl, maxObjectsInGet, maxObjectsInSet);
+        useAuthStore.getState().setUsername(typeof session.username === 'string' ? session.username : null);
 
         const [schemaData, accountData] = await Promise.all([fetchSchema(), fetchAccountInfo()]);
 
diff --git a/src/stores/authStore.ts b/src/stores/authStore.ts
index 34d15a3..6e1a79d 100644
--- a/src/stores/authStore.ts
+++ b/src/stores/authStore.ts
@@ -26,6 +26,8 @@ interface AuthState {
   apiUrl: string | null;
   maxObjectsInGet: number;
   maxObjectsInSet: number;
+  /** INBUXA: who is signed in, from the JMAP session (`username`). */
+  username: string | null;
 
   setTokens: (
     access: string,
@@ -42,6 +44,7 @@ interface AuthState {
     maxObjectsInSet?: number,
   ) => void;
   switchAccount: (accountId: string) => void;
+  setUsername: (username: string | null) => void;
   logout: () => void;
   isAuthenticated: () => boolean;
   isTokenExpiringSoon: () => boolean;
@@ -58,6 +61,11 @@ export const useAuthStore = create<AuthState>()(
       accounts: {},
       primaryAccountId: null,
       activeAccountId: null,
+      username: null,
+
+      setUsername: (username) => {
+        set({ username });
+      },
       apiUrl: null,
       maxObjectsInGet: 500,
       maxObjectsInSet: 500,
@@ -103,6 +111,7 @@ export const useAuthStore = create<AuthState>()(
           primaryAccountId: null,
           activeAccountId: null,
           apiUrl: null,
+          username: null,
         });
       },