diff --git a/components/settings/account-settings.tsx b/components/settings/account-settings.tsx
index 1083e0cb..3e70b9cd 100644
--- a/components/settings/account-settings.tsx
+++ b/components/settings/account-settings.tsx
@@ -3,29 +3,44 @@
 import { useTranslations } from 'next-intl';
 import { useAuthStore } from '@/stores/auth-store';
 import { useEmailStore } from '@/stores/email-store';
+import { useAccountStore } from '@/stores/account-store';
 import { SettingsSection, SettingItem } from './settings-section';
 import { formatFileSize } from '@/lib/utils';
 
 export function AccountSettings() {
   const t = useTranslations('settings.account');
-  const { username, serverUrl, isDemoMode, primaryIdentity } = useAuthStore();
+  const { username, serverUrl, isDemoMode, primaryIdentity, authMode, activeAccountId } = useAuthStore();
   const { quota } = useEmailStore();
+  const account = useAccountStore((s) => activeAccountId ? s.getAccountById(activeAccountId) : undefined);
 
   const quotaPercentage = quota ? Math.round((quota.used / quota.total) * 100) : 0;
-  const displayName = primaryIdentity?.name || (isDemoMode ? 'Demo User' : undefined);
+  const displayName = primaryIdentity?.name || account?.displayName || (isDemoMode ? 'Demo User' : undefined);
+  const email = primaryIdentity?.email || account?.email || username;
 
   return (
     <SettingsSection title={t('title')} description={t('description')}>
-      {/* Display Name (show in demo mode or when identity has a name) */}
-      {displayName && (
-        <SettingItem label={t('name_label')}>
-          <span className="text-sm text-foreground">{displayName}</span>
-        </SettingItem>
-      )}
+      {/* Display Name */}
+      <SettingItem label={t('name_label')}>
+        <span className="text-sm text-foreground">{displayName || t('../../common.unknown')}</span>
+      </SettingItem>
 
       {/* Email Address */}
       <SettingItem label={t('email.label')}>
-        <span className="text-sm text-foreground">{username || t('../../common.unknown')}</span>
+        <span className="text-sm text-foreground">{email || t('../../common.unknown')}</span>
+      </SettingItem>
+
+      {/* Username / Login (show when it differs from email) */}
+      {username && username !== email && (
+        <SettingItem label={t('username_label')}>
+          <span className="text-sm text-foreground">{username}</span>
+        </SettingItem>
+      )}
+
+      {/* Authentication Method */}
+      <SettingItem label={t('auth_method_label')}>
+        <span className="text-sm text-foreground">
+          {authMode === 'oauth' ? t('auth_method_oauth') : t('auth_method_basic')}
+        </span>
       </SettingItem>
 
       {/* Server */}
diff --git a/locales/de/common.json b/locales/de/common.json
index 17cb3f22..264cd1b5 100644
--- a/locales/de/common.json
+++ b/locales/de/common.json
@@ -913,7 +913,11 @@
       "title": "Konto",
       "description": "Zeigen Sie Ihre Kontoinformationen an",
       "name_label": "Anzeigename",
+      "username_label": "Benutzername",
       "account_type_label": "Kontotyp",
+      "auth_method_label": "Authentifizierung",
+      "auth_method_oauth": "Single Sign-On (OAuth/OIDC)",
+      "auth_method_basic": "Passwort",
       "demo_account": "Demokonto",
       "email": {
         "label": "E-Mail-Adresse",
diff --git a/locales/en/common.json b/locales/en/common.json
index 5f6b9e79..6d84985b 100644
--- a/locales/en/common.json
+++ b/locales/en/common.json
@@ -913,7 +913,11 @@
       "title": "Account",
       "description": "View your account information",
       "name_label": "Display Name",
+      "username_label": "Username",
       "account_type_label": "Account Type",
+      "auth_method_label": "Authentication",
+      "auth_method_oauth": "Single Sign-On (OAuth/OIDC)",
+      "auth_method_basic": "Password",
       "demo_account": "Demo Account",
       "email": {
         "label": "Email Address",
diff --git a/locales/es/common.json b/locales/es/common.json
index be56888b..e9eba747 100644
--- a/locales/es/common.json
+++ b/locales/es/common.json
@@ -913,7 +913,11 @@
       "title": "Cuenta",
       "description": "Vea la información de su cuenta",
       "name_label": "Nombre para mostrar",
+      "username_label": "Nombre de usuario",
       "account_type_label": "Tipo de cuenta",
+      "auth_method_label": "Autenticación",
+      "auth_method_oauth": "Inicio de sesión único (OAuth/OIDC)",
+      "auth_method_basic": "Contraseña",
       "demo_account": "Cuenta de demostración",
       "email": {
         "label": "Dirección de Correo",
diff --git a/locales/fr/common.json b/locales/fr/common.json
index d8b2c506..90961771 100644
--- a/locales/fr/common.json
+++ b/locales/fr/common.json
@@ -913,7 +913,11 @@
       "title": "Compte",
       "description": "Consultez les informations de votre compte",
       "name_label": "Nom d'affichage",
+      "username_label": "Nom d'utilisateur",
       "account_type_label": "Type de compte",
+      "auth_method_label": "Authentification",
+      "auth_method_oauth": "Authentification unique (OAuth/OIDC)",
+      "auth_method_basic": "Mot de passe",
       "demo_account": "Compte de démonstration",
       "email": {
         "label": "Adresse email",
diff --git a/locales/it/common.json b/locales/it/common.json
index 580e69df..efc099b6 100644
--- a/locales/it/common.json
+++ b/locales/it/common.json
@@ -913,7 +913,11 @@
       "title": "Account",
       "description": "Visualizza le informazioni del tuo account",
       "name_label": "Nome visualizzato",
+      "username_label": "Nome utente",
       "account_type_label": "Tipo di account",
+      "auth_method_label": "Autenticazione",
+      "auth_method_oauth": "Single Sign-On (OAuth/OIDC)",
+      "auth_method_basic": "Password",
       "demo_account": "Account dimostrativo",
       "email": {
         "label": "Indirizzo email",
diff --git a/locales/ja/common.json b/locales/ja/common.json
index 4b7c6a8c..c5fabf87 100644
--- a/locales/ja/common.json
+++ b/locales/ja/common.json
@@ -913,7 +913,11 @@
       "title": "アカウント",
       "description": "アカウント情報を表示",
       "name_label": "表示名",
+      "username_label": "ユーザー名",
       "account_type_label": "アカウントタイプ",
+      "auth_method_label": "認証方法",
+      "auth_method_oauth": "シングルサインオン (OAuth/OIDC)",
+      "auth_method_basic": "パスワード",
       "demo_account": "デモアカウント",
       "email": {
         "label": "メールアドレス",
diff --git a/locales/nl/common.json b/locales/nl/common.json
index 0820189b..a681520b 100644
--- a/locales/nl/common.json
+++ b/locales/nl/common.json
@@ -913,7 +913,11 @@
       "title": "Account",
       "description": "Bekijk je accountinformatie",
       "name_label": "Weergavenaam",
+      "username_label": "Gebruikersnaam",
       "account_type_label": "Accounttype",
+      "auth_method_label": "Authenticatie",
+      "auth_method_oauth": "Single Sign-On (OAuth/OIDC)",
+      "auth_method_basic": "Wachtwoord",
       "demo_account": "Demoaccount",
       "email": {
         "label": "E-mailadres",
diff --git a/locales/pt/common.json b/locales/pt/common.json
index 9e45864c..325c5235 100644
--- a/locales/pt/common.json
+++ b/locales/pt/common.json
@@ -913,7 +913,11 @@
       "title": "Conta",
       "description": "Visualize as informações da sua conta",
       "name_label": "Nome de exibição",
+      "username_label": "Nome de usuário",
       "account_type_label": "Tipo de conta",
+      "auth_method_label": "Autenticação",
+      "auth_method_oauth": "Login único (OAuth/OIDC)",
+      "auth_method_basic": "Senha",
       "demo_account": "Conta de demonstração",
       "email": {
         "label": "Endereço de E-mail",
diff --git a/stores/auth-store.ts b/stores/auth-store.ts
index 338c43c2..f5f29939 100644
--- a/stores/auth-store.ts
+++ b/stores/auth-store.ts
@@ -486,8 +486,12 @@ export const useAuthStore = create<AuthState>()(
           });
           await client.connect();
 
-          const username = client.getUsername();
-          const { identities, primaryIdentity } = loadIdentities(await client.getIdentities(), username);
+          const jmapUsername = client.getUsername();
+          const { identities, primaryIdentity } = loadIdentities(await client.getIdentities(), jmapUsername);
+          // For OAuth/OIDC, the JMAP session account name may be the
+          // preferred_username claim rather than the real email address.
+          // Prefer the email from the primary identity when available.
+          const username = primaryIdentity?.email || jmapUsername;
           initializeFeatureStores(client);
 
           // Register in account store
@@ -602,8 +606,12 @@ export const useAuthStore = create<AuthState>()(
           });
           await client.connect();
 
-          const username = client.getUsername();
-          const { identities, primaryIdentity } = loadIdentities(await client.getIdentities(), username);
+          const jmapUsername = client.getUsername();
+          const { identities, primaryIdentity } = loadIdentities(await client.getIdentities(), jmapUsername);
+          // For SSO/OIDC, the JMAP session account name may be the
+          // preferred_username claim rather than the real email address.
+          // Prefer the email from the primary identity when available.
+          const username = primaryIdentity?.email || jmapUsername;
           initializeFeatureStores(client);
 
           const accountId = generateAccountId(username, ssoServerUrl);