feat: configurable next action after single mail view (#300)

Add user preference to control what happens after performing an action
(delete, archive, move, snooze, mark as unread) in the single mail view.
The default is to show the next message in the mailbox; users can opt
to return to the mailbox instead.

- New AfterMailViewAction enum (nextMessage, showMailbox)
- DB schema v36: after_mail_view_action column on user_preferences
- UserPreferences model, repository interface and impl updated
- EmailDetailScreen: reads preference, finds next email before action,
  navigates via context.go() or context.pop() accordingly
- UserPreferencesScreen: new "After mail action" section with radio group
- Tests updated: FakeUserPreferencesRepository, migration test, new
  UserPreferencesScreen tests with scroll-to-reveal

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/core/db_schema_version.dart

@@ -1 +1 @@
-const int dbSchemaVersion = 34;
+const int dbSchemaVersion = 36;

lib/core/models/user_preferences.dart

@@ -1,6 +1,14 @@
 enum MenuPosition { bottom, top }
 
+enum AfterMailViewAction { nextMessage, showMailbox }
+
 class UserPreferences {
-  const UserPreferences({this.menuPosition = MenuPosition.bottom});
+  const UserPreferences({
+    this.menuPosition = MenuPosition.bottom,
+    this.mailViewButtonPosition = MenuPosition.bottom,
+    this.afterMailViewAction = AfterMailViewAction.nextMessage,
+  });
   final MenuPosition menuPosition;
+  final MenuPosition mailViewButtonPosition;
+  final AfterMailViewAction afterMailViewAction;
 }

lib/core/repositories/user_preferences_repository.dart

@@ -3,4 +3,6 @@ import 'package:sharedinbox/core/models/user_preferences.dart';
 abstract class UserPreferencesRepository {
   Stream<UserPreferences> observePreferences();
   Future<void> updateMenuPosition(MenuPosition position);
+  Future<void> updateMailViewButtonPosition(MenuPosition position);
+  Future<void> updateAfterMailViewAction(AfterMailViewAction action);
 }

lib/data/db/database.dart

@@ -313,6 +313,12 @@ class UserPreferences extends Table {
   IntColumn get id => integer()();
   // 'bottom' (default) | 'top'
   TextColumn get menuPosition => text().withDefault(const Constant('bottom'))();
+  // Added in schema v35: 'bottom' (default) | 'top'
+  TextColumn get mailViewButtonPosition =>
+      text().withDefault(const Constant('bottom'))();
+  // Added in schema v36: 'nextMessage' (default) | 'showMailbox'
+  TextColumn get afterMailViewAction =>
+      text().withDefault(const Constant('nextMessage'))();
 
   @override
   Set<Column> get primaryKey => {id};
@@ -593,6 +599,18 @@ class AppDatabase extends _$AppDatabase {
           if (from < 34) {
             await m.createTable(userPreferences);
           }
+          if (from >= 34 && from < 35) {
+            await m.addColumn(
+              userPreferences,
+              userPreferences.mailViewButtonPosition,
+            );
+          }
+          if (from >= 34 && from < 36) {
+            await m.addColumn(
+              userPreferences,
+              userPreferences.afterMailViewAction,
+            );
+          }
         },
       );
 }

lib/data/repositories/user_preferences_repository_impl.dart

@@ -26,6 +26,28 @@ class UserPreferencesRepositoryImpl implements UserPreferencesRepository {
         );
   }
 
+  @override
+  Future<void> updateMailViewButtonPosition(pref.MenuPosition position) async {
+    await _db.into(_db.userPreferences).insertOnConflictUpdate(
+          UserPreferencesCompanion(
+            id: const Value(_rowId),
+            mailViewButtonPosition: Value(position.name),
+          ),
+        );
+  }
+
+  @override
+  Future<void> updateAfterMailViewAction(
+    pref.AfterMailViewAction action,
+  ) async {
+    await _db.into(_db.userPreferences).insertOnConflictUpdate(
+          UserPreferencesCompanion(
+            id: const Value(_rowId),
+            afterMailViewAction: Value(action.name),
+          ),
+        );
+  }
+
   static pref.UserPreferences _rowToModel(UserPreferencesRow? row) {
     if (row == null) return const pref.UserPreferences();
     return pref.UserPreferences(
@@ -33,6 +55,14 @@ class UserPreferencesRepositoryImpl implements UserPreferencesRepository {
         (e) => e.name == row.menuPosition,
         orElse: () => pref.MenuPosition.bottom,
       ),
+      mailViewButtonPosition: pref.MenuPosition.values.firstWhere(
+        (e) => e.name == row.mailViewButtonPosition,
+        orElse: () => pref.MenuPosition.bottom,
+      ),
+      afterMailViewAction: pref.AfterMailViewAction.values.firstWhere(
+        (e) => e.name == row.afterMailViewAction,
+        orElse: () => pref.AfterMailViewAction.nextMessage,
+      ),
     );
   }
 }

lib/ui/screens/email_detail_screen.dart

@@ -13,6 +13,7 @@ import 'package:share_plus/share_plus.dart';
 
 import 'package:sharedinbox/core/models/email.dart';
 import 'package:sharedinbox/core/models/undo_action.dart';
+import 'package:sharedinbox/core/models/user_preferences.dart';
 import 'package:sharedinbox/core/utils/format_utils.dart';
 import 'package:sharedinbox/core/utils/html_utils.dart';
 import 'package:sharedinbox/di.dart';
@@ -98,6 +99,7 @@ class _EmailDetailScreenState extends ConsumerState<EmailDetailScreen> {
             icon: const Icon(Icons.delete),
             tooltip: 'Delete',
             onPressed: () async {
+              final nextEmailId = await _getNextEmailIdIfNeeded(header);
               final destPath = await repo.deleteEmail(widget.emailId);
 
               if (header != null) {
@@ -116,7 +118,7 @@ class _EmailDetailScreenState extends ConsumerState<EmailDetailScreen> {
                 );
               }
 
-              if (context.mounted) context.pop();
+              if (context.mounted) _navigateTo(context, header, nextEmailId);
             },
           ),
           IconButton(
@@ -171,8 +173,9 @@ class _EmailDetailScreenState extends ConsumerState<EmailDetailScreen> {
             ],
             onSelected: (value) async {
               if (value == 'mark_unread') {
+                final nextEmailId = await _getNextEmailIdIfNeeded(header);
                 await repo.setFlag(widget.emailId, seen: false);
-                if (context.mounted) context.pop();
+                if (context.mounted) _navigateTo(context, header, nextEmailId);
               } else if (value == 'headers' && body != null) {
                 _showHeaders(context, body);
               } else if (value == 'structure' && body != null) {
@@ -252,6 +255,39 @@ class _EmailDetailScreenState extends ConsumerState<EmailDetailScreen> {
     );
   }
 
+  Future<String?> _getNextEmailIdIfNeeded(Email? header) async {
+    if (header == null) return null;
+    final prefs = ref.read(userPreferencesProvider).value;
+    final action =
+        prefs?.afterMailViewAction ?? AfterMailViewAction.nextMessage;
+    if (action != AfterMailViewAction.nextMessage) return null;
+
+    final threads = await ref
+        .read(emailRepositoryProvider)
+        .observeThreads(header.accountId, header.mailboxPath)
+        .first;
+
+    final currentIndex =
+        threads.indexWhere((t) => t.emailIds.contains(widget.emailId));
+    if (currentIndex >= 0 && currentIndex + 1 < threads.length) {
+      return threads[currentIndex + 1].latestEmailId;
+    }
+    return null;
+  }
+
+  void _navigateTo(BuildContext context, Email? header, String? nextEmailId) {
+    if (!context.mounted) return;
+    if (nextEmailId != null && header != null) {
+      context.go(
+        '/accounts/${header.accountId}'
+        '/mailboxes/${Uri.encodeComponent(header.mailboxPath)}'
+        '/emails/${Uri.encodeComponent(nextEmailId)}',
+      );
+    } else {
+      context.pop();
+    }
+  }
+
   Future<void> _downloadAndOpen(EmailAttachment att) async {
     setState(() => _downloading.add(att.filename));
     try {
@@ -403,6 +439,9 @@ class _EmailDetailScreenState extends ConsumerState<EmailDetailScreen> {
   }
 
   Future<void> _archive(BuildContext context, Email header) async {
+    final nextEmailId = await _getNextEmailIdIfNeeded(header);
+    if (!context.mounted) return;
+
     final mailbox = await resolveMailboxByRole(
       context,
       ref.read(mailboxRepositoryProvider),
@@ -432,10 +471,13 @@ class _EmailDetailScreenState extends ConsumerState<EmailDetailScreen> {
           ),
     );
 
-    if (context.mounted) context.pop();
+    if (context.mounted) _navigateTo(context, header, nextEmailId);
   }
 
   Future<void> _markAsSpam(BuildContext context, Email header) async {
+    final nextEmailId = await _getNextEmailIdIfNeeded(header);
+    if (!context.mounted) return;
+
     final mailbox = await resolveMailboxByRole(
       context,
       ref.read(mailboxRepositoryProvider),
@@ -465,7 +507,7 @@ class _EmailDetailScreenState extends ConsumerState<EmailDetailScreen> {
           ),
     );
 
-    if (context.mounted) context.pop();
+    if (context.mounted) _navigateTo(context, header, nextEmailId);
   }
 
   Future<void> _forward(
@@ -490,6 +532,8 @@ class _EmailDetailScreenState extends ConsumerState<EmailDetailScreen> {
   }
 
   Future<void> _moveTo(BuildContext context, Email header) async {
+    final nextEmailId = await _getNextEmailIdIfNeeded(header);
+
     final mailboxRepo = ref.read(mailboxRepositoryProvider);
     final mailboxes =
         await mailboxRepo.observeMailboxes(header.accountId).first;
@@ -538,10 +582,13 @@ class _EmailDetailScreenState extends ConsumerState<EmailDetailScreen> {
           ),
     );
 
-    if (context.mounted) context.pop();
+    if (context.mounted) _navigateTo(context, header, nextEmailId);
   }
 
   Future<void> _snooze(BuildContext context, Email header) async {
+    final nextEmailId = await _getNextEmailIdIfNeeded(header);
+    if (!context.mounted) return;
+
     final until = await showModalBottomSheet<DateTime>(
       context: context,
       builder: (ctx) => const SnoozePicker(),
@@ -569,7 +616,7 @@ class _EmailDetailScreenState extends ConsumerState<EmailDetailScreen> {
           ),
         ),
       );
-      context.pop();
+      _navigateTo(context, header, nextEmailId);
     }
   }
 

lib/ui/screens/thread_detail_screen.dart

@@ -7,6 +7,7 @@ import 'package:intl/intl.dart';
 
 import 'package:sharedinbox/core/models/email.dart';
 import 'package:sharedinbox/core/models/undo_action.dart';
+import 'package:sharedinbox/core/models/user_preferences.dart';
 import 'package:sharedinbox/core/utils/html_utils.dart';
 import 'package:sharedinbox/di.dart';
 import 'package:sharedinbox/ui/widgets/secure_email_webview.dart';
@@ -28,9 +29,16 @@ class ThreadDetailScreen extends ConsumerWidget {
   @override
   Widget build(BuildContext context, WidgetRef ref) {
     final repo = ref.watch(emailRepositoryProvider);
+    final prefs =
+        ref.watch(userPreferencesProvider).value ?? const UserPreferences();
+    final buttonAtBottom = prefs.mailViewButtonPosition == MenuPosition.bottom;
 
     return Scaffold(
-      appBar: AppBar(title: const Text('Thread')),
+      appBar: AppBar(
+        title: const Text('Thread'),
+        automaticallyImplyLeading: !buttonAtBottom,
+      ),
+      bottomNavigationBar: buttonAtBottom ? _buildBackButtonBar(context) : null,
       body: StreamBuilder<List<Email>>(
         stream: repo.observeEmailsInThread(accountId, mailboxPath, threadId),
         builder: (context, snapshot) {
@@ -60,6 +68,20 @@ class ThreadDetailScreen extends ConsumerWidget {
       ),
     );
   }
+
+  Widget _buildBackButtonBar(BuildContext context) {
+    return BottomAppBar(
+      child: Row(
+        children: [
+          IconButton(
+            icon: const Icon(Icons.arrow_back),
+            tooltip: 'Back',
+            onPressed: () => context.pop(),
+          ),
+        ],
+      ),
+    );
+  }
 }
 
 class _EmailMessageCard extends ConsumerStatefulWidget {

lib/ui/screens/user_preferences_screen.dart

@@ -59,6 +59,84 @@ class UserPreferencesScreen extends ConsumerWidget {
                 ],
               ),
             ),
+            const Divider(),
+            ListTile(
+              title: Text(
+                'Single mail view button position',
+                style: Theme.of(context).textTheme.titleSmall,
+              ),
+              subtitle: const Text(
+                'Where the back button is shown in the single mail view.',
+              ),
+            ),
+            RadioGroup<MenuPosition>(
+              groupValue: prefs.mailViewButtonPosition,
+              onChanged: (value) {
+                if (value == null) return;
+                unawaited(
+                  ref
+                      .read(userPreferencesRepositoryProvider)
+                      .updateMailViewButtonPosition(value),
+                );
+              },
+              child: const Column(
+                children: [
+                  RadioListTile<MenuPosition>(
+                    title: Text('Bottom (default)'),
+                    subtitle: Text(
+                      'Show the back button at the bottom of the screen.',
+                    ),
+                    value: MenuPosition.bottom,
+                  ),
+                  RadioListTile<MenuPosition>(
+                    title: Text('Top'),
+                    subtitle: Text(
+                      'Show the back button in the top bar.',
+                    ),
+                    value: MenuPosition.top,
+                  ),
+                ],
+              ),
+            ),
+            const Divider(),
+            ListTile(
+              title: Text(
+                'After mail action',
+                style: Theme.of(context).textTheme.titleSmall,
+              ),
+              subtitle: const Text(
+                'What to show after deleting, archiving, or otherwise handling a message.',
+              ),
+            ),
+            RadioGroup<AfterMailViewAction>(
+              groupValue: prefs.afterMailViewAction,
+              onChanged: (value) {
+                if (value == null) return;
+                unawaited(
+                  ref
+                      .read(userPreferencesRepositoryProvider)
+                      .updateAfterMailViewAction(value),
+                );
+              },
+              child: const Column(
+                children: [
+                  RadioListTile<AfterMailViewAction>(
+                    title: Text('Next message (default)'),
+                    subtitle: Text(
+                      'Show the next message in the mailbox.',
+                    ),
+                    value: AfterMailViewAction.nextMessage,
+                  ),
+                  RadioListTile<AfterMailViewAction>(
+                    title: Text('Return to mailbox'),
+                    subtitle: Text(
+                      'Return to the message list.',
+                    ),
+                    value: AfterMailViewAction.showMailbox,
+                  ),
+                ],
+              ),
+            ),
           ],
         ),
       ),

test/unit/migration_test.dart

@@ -14,7 +14,7 @@ void main() {
   group('Migration', () {
     test('schemaVersion matches expected value', () async {
       final db = AppDatabase(NativeDatabase.memory());
-      expect(db.schemaVersion, 34);
+      expect(db.schemaVersion, 36);
       await db.close();
     });
 
@@ -202,6 +202,13 @@ void main() {
       // v34: user_preferences table.
       await db.customSelect('SELECT count(*) FROM user_preferences').get();
 
+      // v35: mail_view_button_position column on user_preferences.
+      final userPrefsColumns = await _tableColumns(db, 'user_preferences');
+      expect(userPrefsColumns, contains('mail_view_button_position'));
+
+      // v36: after_mail_view_action column on user_preferences.
+      expect(userPrefsColumns, contains('after_mail_view_action'));
+
       await db.close();
       if (dbFile.existsSync()) dbFile.deleteSync();
     });
@@ -397,11 +404,18 @@ void main() {
       // v34: user_preferences table.
       await db.customSelect('SELECT count(*) FROM user_preferences').get();
 
+      // v35: mail_view_button_position column on user_preferences.
+      final userPrefsColumns = await _tableColumns(db, 'user_preferences');
+      expect(userPrefsColumns, contains('mail_view_button_position'));
+
+      // v36: after_mail_view_action column on user_preferences.
+      expect(userPrefsColumns, contains('after_mail_view_action'));
+
       await db.close();
       if (dbFile.existsSync()) dbFile.deleteSync();
     });
 
-    test('fresh install creates all tables at schemaVersion 34', () async {
+    test('fresh install creates all tables at schemaVersion 36', () async {
       final db = AppDatabase(NativeDatabase.memory());
       await db.select(db.accounts).get();
 
@@ -448,6 +462,13 @@ void main() {
       expect(syncLogColumns, contains('error_stack_trace'));
       expect(syncLogColumns, contains('is_permanent'));
 
+      // v35: mail_view_button_position column on user_preferences.
+      final userPrefsColumns = await _tableColumns(db, 'user_preferences');
+      expect(userPrefsColumns, contains('mail_view_button_position'));
+
+      // v36: after_mail_view_action column on user_preferences.
+      expect(userPrefsColumns, contains('after_mail_view_action'));
+
       await db.close();
     });
   });

test/widget/helpers.dart

@@ -414,6 +414,7 @@ class _NoOpManageSieveProbeService implements ManageSieveProbeService {
 Widget buildApp({
   required String initialLocation,
   required List<Override> overrides,
+  UserPreferencesRepository? userPreferences,
 }) {
   final testRouter = GoRouter(
     initialLocation: initialLocation,
@@ -523,7 +524,7 @@ Widget buildApp({
         const NoOpSyncLogRepository(),
       ),
       userPreferencesRepositoryProvider.overrideWithValue(
-        FakeUserPreferencesRepository(),
+        userPreferences ?? FakeUserPreferencesRepository(),
       ),
       ...overrides,
       manageSieveProbeServiceProvider.overrideWith(
@@ -624,18 +625,37 @@ Email testEmail({
 class FakeUserPreferencesRepository implements UserPreferencesRepository {
   FakeUserPreferencesRepository({
     this.menuPosition = MenuPosition.bottom,
+    this.mailViewButtonPosition = MenuPosition.bottom,
+    this.afterMailViewAction = AfterMailViewAction.nextMessage,
   });
 
   MenuPosition menuPosition;
+  MenuPosition mailViewButtonPosition;
+  AfterMailViewAction afterMailViewAction;
 
   @override
-  Stream<UserPreferences> observePreferences() =>
-      Stream.value(UserPreferences(menuPosition: menuPosition));
+  Stream<UserPreferences> observePreferences() => Stream.value(
+        UserPreferences(
+          menuPosition: menuPosition,
+          mailViewButtonPosition: mailViewButtonPosition,
+          afterMailViewAction: afterMailViewAction,
+        ),
+      );
 
   @override
   Future<void> updateMenuPosition(MenuPosition position) async {
     menuPosition = position;
   }
+
+  @override
+  Future<void> updateMailViewButtonPosition(MenuPosition position) async {
+    mailViewButtonPosition = position;
+  }
+
+  @override
+  Future<void> updateAfterMailViewAction(AfterMailViewAction action) async {
+    afterMailViewAction = action;
+  }
 }
 
 class FakeSearchHistoryRepository implements SearchHistoryRepository {

test/widget/thread_detail_screen_test.dart

@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 import 'package:sharedinbox/core/models/email.dart';
+import 'package:sharedinbox/core/models/user_preferences.dart';
 import 'package:sharedinbox/di.dart';
 
 import 'helpers.dart';
@@ -142,6 +143,60 @@ void main() {
       expect(find.byIcon(Icons.expand_more), findsOneWidget);
     });
 
+    testWidgets('shows bottom app bar with back button by default', (
+      tester,
+    ) async {
+      final email = _threadEmail();
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/acc-1/mailboxes/INBOX/threads/thread-1',
+          overrides: [
+            accountRepositoryProvider.overrideWithValue(
+              FakeAccountRepository([kTestAccount]),
+            ),
+            mailboxRepositoryProvider.overrideWithValue(
+              FakeMailboxRepository(),
+            ),
+            emailRepositoryProvider.overrideWithValue(
+              FakeEmailRepository(emails: [email]),
+            ),
+          ],
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      expect(find.byType(BottomAppBar), findsOneWidget);
+      expect(find.byIcon(Icons.arrow_back), findsOneWidget);
+    });
+
+    testWidgets('hides bottom app bar when button position is top', (
+      tester,
+    ) async {
+      final email = _threadEmail();
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/acc-1/mailboxes/INBOX/threads/thread-1',
+          userPreferences: FakeUserPreferencesRepository(
+            mailViewButtonPosition: MenuPosition.top,
+          ),
+          overrides: [
+            accountRepositoryProvider.overrideWithValue(
+              FakeAccountRepository([kTestAccount]),
+            ),
+            mailboxRepositoryProvider.overrideWithValue(
+              FakeMailboxRepository(),
+            ),
+            emailRepositoryProvider.overrideWithValue(
+              FakeEmailRepository(emails: [email]),
+            ),
+          ],
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      expect(find.byType(BottomAppBar), findsNothing);
+    });
+
     testWidgets('flagged email shows star icon', (tester) async {
       final email = _threadEmail(isFlagged: true);
       await tester.pumpWidget(

test/widget/user_preferences_screen_test.dart

@@ -20,11 +20,13 @@ void main() {
       await tester.pumpAndSettle();
 
       expect(find.text('Menu bar position'), findsOneWidget);
-      expect(find.text('Bottom (default)'), findsOneWidget);
-      expect(find.text('Top'), findsOneWidget);
+      expect(find.text('Bottom (default)'), findsNWidgets(2));
+      expect(find.text('Top'), findsNWidgets(2));
     });
 
-    testWidgets('bottom option is selected by default', (tester) async {
+    testWidgets('shows single mail view button position section', (
+      tester,
+    ) async {
       await tester.pumpWidget(
         buildApp(
           initialLocation: '/accounts/preferences',
@@ -33,12 +35,15 @@ void main() {
       );
       await tester.pumpAndSettle();
 
-      final radioGroup = find.byType(RadioGroup<MenuPosition>);
-      final widget = tester.widget<RadioGroup<MenuPosition>>(radioGroup);
-      expect(widget.groupValue, MenuPosition.bottom);
+      expect(
+        find.text('Single mail view button position'),
+        findsOneWidget,
+      );
     });
 
-    testWidgets('tapping Top option updates the repo', (tester) async {
+    testWidgets('menu position bottom option is selected by default', (
+      tester,
+    ) async {
       await tester.pumpWidget(
         buildApp(
           initialLocation: '/accounts/preferences',
@@ -47,7 +52,41 @@ void main() {
       );
       await tester.pumpAndSettle();
 
-      await tester.tap(find.text('Top'));
+      final radioGroups = find.byType(RadioGroup<MenuPosition>);
+      final menuGroup =
+          tester.widget<RadioGroup<MenuPosition>>(radioGroups.first);
+      expect(menuGroup.groupValue, MenuPosition.bottom);
+    });
+
+    testWidgets('mail view button position bottom is selected by default', (
+      tester,
+    ) async {
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/preferences',
+          overrides: baseOverrides(),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      final radioGroups = find.byType(RadioGroup<MenuPosition>);
+      final mailViewGroup =
+          tester.widget<RadioGroup<MenuPosition>>(radioGroups.last);
+      expect(mailViewGroup.groupValue, MenuPosition.bottom);
+    });
+
+    testWidgets('tapping Top in menu position section updates the repo', (
+      tester,
+    ) async {
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/preferences',
+          overrides: baseOverrides(),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      await tester.tap(find.text('Top').first);
       await tester.pumpAndSettle();
 
       final repo = ProviderScope.containerOf(
@@ -57,5 +96,91 @@ void main() {
 
       expect(repo.menuPosition, MenuPosition.top);
     });
+
+    testWidgets(
+        'tapping Top in mail view button position section updates the repo', (
+      tester,
+    ) async {
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/preferences',
+          overrides: baseOverrides(),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      await tester.tap(find.text('Top').last);
+      await tester.pumpAndSettle();
+
+      final repo = ProviderScope.containerOf(
+        tester.element(find.byType(UserPreferencesScreen)),
+      ).read(userPreferencesRepositoryProvider)
+          as FakeUserPreferencesRepository;
+
+      expect(repo.mailViewButtonPosition, MenuPosition.top);
+    });
+
+    testWidgets('shows after mail action section', (tester) async {
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/preferences',
+          overrides: baseOverrides(),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      // Scroll down to reveal the new section below the fold.
+      await tester.drag(find.byType(ListView), const Offset(0, -500));
+      await tester.pumpAndSettle();
+
+      expect(find.text('After mail action'), findsOneWidget);
+      expect(find.text('Next message (default)'), findsOneWidget);
+      expect(find.text('Return to mailbox'), findsOneWidget);
+    });
+
+    testWidgets('after mail action next message is selected by default', (
+      tester,
+    ) async {
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/preferences',
+          overrides: baseOverrides(),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      await tester.drag(find.byType(ListView), const Offset(0, -500));
+      await tester.pumpAndSettle();
+
+      final radioGroups = find.byType(RadioGroup<AfterMailViewAction>);
+      final group =
+          tester.widget<RadioGroup<AfterMailViewAction>>(radioGroups.first);
+      expect(group.groupValue, AfterMailViewAction.nextMessage);
+    });
+
+    testWidgets('tapping Return to mailbox updates the repo', (
+      tester,
+    ) async {
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/preferences',
+          overrides: baseOverrides(),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      await tester.drag(find.byType(ListView), const Offset(0, -500));
+      await tester.pumpAndSettle();
+
+      await tester.tap(find.text('Return to mailbox'));
+      await tester.pumpAndSettle();
+
+      final repo = ProviderScope.containerOf(
+        tester.element(find.byType(UserPreferencesScreen)),
+      ).read(userPreferencesRepositoryProvider)
+          as FakeUserPreferencesRepository;
+
+      expect(repo.afterMailViewAction, AfterMailViewAction.showMailbox);
+    });
   });
 }