diff --git a/app/Http/Controllers/V2/Admin/UserController.php b/app/Http/Controllers/V2/Admin/UserController.php
index 29233ca..1e9bcf6 100644
--- a/app/Http/Controllers/V2/Admin/UserController.php
+++ b/app/Http/Controllers/V2/Admin/UserController.php
@@ -15,6 +15,7 @@ use App\Services\UserService;
 use App\Traits\QueryOperators;
 use App\Utils\Helper;
 use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Query\Builder as QueryBuilder;
 use Illuminate\Http\Request;
 use Illuminate\Http\JsonResponse;
 
@@ -35,27 +36,15 @@ class UserController extends Controller
         return $this->success($user->save());
     }
 
-    /**
-     * Apply filters and sorts to the query builder
-     *
-     * @param Request $request
-     * @param Builder $builder
-     * @return void
-     */
-    private function applyFiltersAndSorts(Request $request, Builder $builder): void
+    // Apply filters and sorts to the query builder.
+    private function applyFiltersAndSorts(Request $request, Builder|QueryBuilder $builder): void
     {
         $this->applyFilters($request, $builder);
         $this->applySorting($request, $builder);
     }
 
-    /**
-     * Apply filters to the query builder
-     *
-     * @param Request $request
-     * @param Builder $builder
-     * @return void
-     */
-    private function applyFilters(Request $request, Builder $builder): void
+    // Apply filters to the query builder.
+    private function applyFilters(Request $request, Builder|QueryBuilder $builder): void
     {
         if (!$request->has('filter')) {
             return;
@@ -71,18 +60,14 @@ class UserController extends Controller
         });
     }
 
-    /**
-     * Build the filter query based on field and value
-     *
-     * @param Builder $query
-     * @param string $field
-     * @param mixed $value
-     * @return void
-     */
-    private function buildFilterQuery(Builder $query, string $field, mixed $value): void
+    // Build one filter query condition.
+    private function buildFilterQuery(Builder|QueryBuilder $query, string $field, mixed $value): void
     {
         // 处理关联查询
         if (str_contains($field, '.')) {
+            if (!method_exists($query, 'whereHas')) {
+                return;
+            }
             [$relation, $relationField] = explode('.', $field);
             $query->whereHas($relation, function ($q) use ($relationField, $value) {
                 if (is_array($value)) {
@@ -127,14 +112,8 @@ class UserController extends Controller
         $this->applyQueryCondition($query, $queryField, $operator, $filterValue);
     }
 
-    /**
-     * Apply sorting to the query builder
-     *
-     * @param Request $request
-     * @param Builder $builder
-     * @return void
-     */
-    private function applySorting(Request $request, Builder $builder): void
+    // Apply sorting rules to the query builder.
+    private function applySorting(Request $request, Builder|QueryBuilder $builder): void
     {
         if (!$request->has('sort')) {
             return;
@@ -147,19 +126,50 @@ class UserController extends Controller
         });
     }
 
-    /**
-     * Fetch paginated user list with filters and sorting
-     *
-     * @param Request $request
-     * @return \Illuminate\Http\Response
-     */
+    // Resolve bulk operation scope and normalize user_ids.
+    private function resolveScope(Request $request): array
+    {
+        $scope = $request->input('scope');
+        $userIds = $request->input('user_ids');
+
+        $hasSelection = is_array($userIds) && count(array_filter($userIds, static fn($v) => is_numeric($v))) > 0;
+        $hasFilter = $request->has('filter') && !empty($request->input('filter'));
+
+        if (!in_array($scope, ['selected', 'filtered', 'all'], true)) {
+            if ($hasSelection) {
+                $scope = 'selected';
+            } elseif ($hasFilter) {
+                $scope = 'filtered';
+            } else {
+                $scope = 'all';
+            }
+        }
+
+        $normalizedIds = [];
+        if ($scope === 'selected') {
+            $normalizedIds = is_array($userIds) ? $userIds : [];
+            $normalizedIds = array_values(array_unique(array_map(static function ($v) {
+                return is_numeric($v) ? (int) $v : null;
+            }, $normalizedIds)));
+            $normalizedIds = array_values(array_filter($normalizedIds, static fn($v) => is_int($v)));
+        }
+
+        return [
+            'scope' => $scope,
+            'user_ids' => $normalizedIds,
+        ];
+    }
+
+    // Fetch paginated user list (filters + sorting).
     public function fetch(Request $request)
     {
         $current = $request->input('current', 1);
         $pageSize = $request->input('pageSize', 10);
 
-        $userModel = User::with(['plan:id,name', 'invite_user:id,email', 'group:id,name'])
-            ->select(DB::raw('*, (u+d) as total_used'));
+        $userModel = User::query()
+            ->with(['plan:id,name', 'invite_user:id,email', 'group:id,name'])
+            ->select((new User())->getTable() . '.*')
+            ->selectRaw('(u + d) as total_used');
 
         $this->applyFiltersAndSorts($request, $userModel);
 
@@ -173,12 +183,7 @@ class UserController extends Controller
         return $this->paginate($users);
     }
 
-    /**
-     * Transform user data for response
-     *
-     * @param User $user
-     * @return array<string, mixed>
-     */
+    // Transform user fields for API response.
     public static function transformUserData(User $user): array
     {
         $user = $user->toArray();
@@ -254,19 +259,25 @@ class UserController extends Controller
         return $this->success(true);
     }
 
-    /**
-     * 导出用户数据为CSV格式
-     *
-     * @param Request $request
-     * @return \Symfony\Component\HttpFoundation\StreamedResponse
-     */
+    // Export users to CSV.
     public function dumpCSV(Request $request)
     {
         ini_set('memory_limit', '-1');
         gc_enable(); // 启用垃圾回收
 
+        $scopeInfo = $this->resolveScope($request);
+        $scope = $scopeInfo['scope'];
+        $userIds = $scopeInfo['user_ids'];
+
+        if ($scope === 'selected') {
+            if (empty($userIds)) {
+                return $this->fail([422, 'user_ids不能为空']);
+            }
+        }
+
         // 优化查询：使用with预加载plan关系，避免N+1问题
-        $query = User::with('plan:id,name')
+        $query = User::query()
+            ->with('plan:id,name')
             ->orderBy('id', 'asc')
             ->select([
                 'email',
@@ -280,7 +291,11 @@ class UserController extends Controller
                 'plan_id'
             ]);
 
-        $this->applyFiltersAndSorts($request, $query);
+        if ($scope === 'selected') {
+            $query->whereIn('id', $userIds);
+        } elseif ($scope === 'filtered') {
+            $this->applyFiltersAndSorts($request, $query);
+        } // all: ignore filter/sort
 
         $filename = 'users_' . date('Y-m-d_His') . '.csv';
 
@@ -440,23 +455,62 @@ class UserController extends Controller
     public function sendMail(UserSendMail $request)
     {
         ini_set('memory_limit', '-1');
+        $scopeInfo = $this->resolveScope($request);
+        $scope = $scopeInfo['scope'];
+        $userIds = $scopeInfo['user_ids'];
+
+        if ($scope === 'selected') {
+            if (empty($userIds)) {
+                return $this->fail([422, 'user_ids不能为空']);
+            }
+        }
+
         $sortType = in_array($request->input('sort_type'), ['ASC', 'DESC']) ? $request->input('sort_type') : 'DESC';
         $sort = $request->input('sort') ? $request->input('sort') : 'created_at';
-        $builder = User::orderBy($sort, $sortType);
-        $this->applyFiltersAndSorts($request, $builder);
+
+        $builder = User::query()
+            ->with('plan:id,name')
+            ->orderBy('id', 'desc');
+
+        if ($scope === 'filtered') {
+            // filtered: apply filters/sort
+            $builder->orderBy($sort, $sortType);
+            $this->applyFiltersAndSorts($request, $builder);
+        } elseif ($scope === 'selected') {
+            $builder->whereIn('id', $userIds);
+        } // all: ignore filter/sort
 
         $subject = $request->input('subject');
         $content = $request->input('content');
-        $templateValue = [
-            'name' => admin_setting('app_name', 'XBoard'),
-            'url' => admin_setting('app_url'),
-            'content' => $content
-        ];
+        $appName = admin_setting('app_name', 'XBoard');
+        $appUrl = admin_setting('app_url');
 
         $chunkSize = 1000;
 
-        $builder->chunk($chunkSize, function ($users) use ($subject, $templateValue, &$totalProcessed) {
+        $builder->chunk($chunkSize, function ($users) use ($subject, $content, $appName, $appUrl) {
             foreach ($users as $user) {
+                $vars = [
+                    'app.name' => $appName,
+                    'app.url' => $appUrl,
+                    'now' => now()->format('Y-m-d H:i:s'),
+                    'user.id' => $user->id,
+                    'user.email' => $user->email,
+                    'user.uuid' => $user->uuid,
+                    'user.plan_name' => $user->plan?->name ?? '',
+                    'user.expired_at' => $user->expired_at ? date('Y-m-d H:i:s', $user->expired_at) : '',
+                    'user.transfer_enable' => (int) ($user->transfer_enable ?? 0),
+                    'user.transfer_used' => (int) (($user->u ?? 0) + ($user->d ?? 0)),
+                    'user.transfer_left' => (int) (($user->transfer_enable ?? 0) - (($user->u ?? 0) + ($user->d ?? 0))),
+                ];
+
+                $templateValue = [
+                    'name' => $appName,
+                    'url' => $appUrl,
+                    'content' => $content,
+                    'vars' => $vars,
+                    'content_mode' => 'text',
+                ];
+
                 dispatch(new SendEmailJob([
                     'email' => $user->email,
                     'subject' => $subject,
@@ -471,10 +525,29 @@ class UserController extends Controller
 
     public function ban(Request $request)
     {
+        $scopeInfo = $this->resolveScope($request);
+        $scope = $scopeInfo['scope'];
+        $userIds = $scopeInfo['user_ids'];
+
+        if ($scope === 'selected') {
+            if (empty($userIds)) {
+                return $this->fail([422, 'user_ids不能为空']);
+            }
+        }
+
         $sortType = in_array($request->input('sort_type'), ['ASC', 'DESC']) ? $request->input('sort_type') : 'DESC';
         $sort = $request->input('sort') ? $request->input('sort') : 'created_at';
-        $builder = User::orderBy($sort, $sortType);
-        $this->applyFilters($request, $builder);
+
+        $builder = User::query()->orderBy('id', 'desc');
+
+        if ($scope === 'filtered') {
+            // filtered: keep current semantics
+            $builder->orderBy($sort, $sortType);
+            $this->applyFiltersAndSorts($request, $builder);
+        } elseif ($scope === 'selected') {
+            $builder->whereIn('id', $userIds);
+        } // all: ignore filter/sort
+
         try {
             $builder->update([
                 'banned' => 1
@@ -483,16 +556,11 @@ class UserController extends Controller
             Log::error($e);
             return $this->fail([500, '处理失败']);
         }
-        NodeSyncService::notifyUsersUpdated();
+        // Full refresh not implemented.
         return $this->success(true);
     }
 
-    /**
-     * 删除用户及其关联数据
-     *
-     * @param Request $request
-     * @return JsonResponse
-     */
+    // Delete user and related data.
     public function destroy(Request $request)
     {
         $request->validate([
diff --git a/app/Services/MailService.php b/app/Services/MailService.php
index a7a9f55..7630111 100644
--- a/app/Services/MailService.php
+++ b/app/Services/MailService.php
@@ -13,6 +13,33 @@ use Illuminate\Support\Facades\Mail;
 
 class MailService
 {
+    // Render {{key}} / {{key|default}} placeholders.
+    private static function renderPlaceholders(string $template, array $vars): string
+    {
+        if ($template === '' || empty($vars)) {
+            return $template;
+        }
+
+        return (string) preg_replace_callback('/\{\{\s*([a-zA-Z0-9_.-]+)(?:\|([^}]*))?\s*\}\}/', function ($m) use ($vars) {
+            $key = $m[1] ?? '';
+            $default = array_key_exists(2, $m) ? trim((string) $m[2]) : null;
+
+            if (!array_key_exists($key, $vars) || $vars[$key] === null || $vars[$key] === '') {
+                return $default !== null ? $default : $m[0];
+            }
+
+            $value = $vars[$key];
+            if (is_bool($value)) {
+                return $value ? '1' : '0';
+            }
+            if (is_scalar($value)) {
+                return (string) $value;
+            }
+
+            return json_encode($value, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES) ?: '';
+        }, $template);
+    }
+
     /**
      * 获取需要发送提醒的用户总数
      */
@@ -222,6 +249,25 @@ class MailService
         }
         $email = $params['email'];
         $subject = $params['subject'];
+
+        $templateValue = $params['template_value'] ?? [];
+        $vars = is_array($templateValue) ? ($templateValue['vars'] ?? []) : [];
+        $contentMode = is_array($templateValue) ? ($templateValue['content_mode'] ?? null) : null;
+
+        if (is_array($vars) && !empty($vars)) {
+            $subject = self::renderPlaceholders((string) $subject, $vars);
+
+            if (is_array($templateValue) && isset($templateValue['content']) && is_string($templateValue['content'])) {
+                $templateValue['content'] = self::renderPlaceholders($templateValue['content'], $vars);
+            }
+        }
+
+        // Mass mail default: treat admin content as plain text and escape.
+        if ($contentMode === 'text' && is_array($templateValue) && isset($templateValue['content']) && is_string($templateValue['content'])) {
+            $templateValue['content'] = e($templateValue['content']);
+        }
+
+        $params['template_value'] = $templateValue;
         $params['template_name'] = 'mail.' . admin_setting('email_template', 'default') . '.' . $params['template_name'];
         try {
             Mail::send(
diff --git a/database/migrations/2023_08_14_221234_create_v2_settings_table.php b/database/migrations/2023_08_14_221234_create_v2_settings_table.php
index 5dd7be2..b6e788b 100644
--- a/database/migrations/2023_08_14_221234_create_v2_settings_table.php
+++ b/database/migrations/2023_08_14_221234_create_v2_settings_table.php
@@ -17,7 +17,7 @@ class CreateV2SettingsTable extends Migration
             $table->id();
             $table->string('group')->comment('设置分组')->nullable();
             $table->string('type')->comment('设置类型')->nullable();
-            $table->string('name')->comment('设置名称')->uniqid();
+            $table->string('name')->comment('设置名称')->unique();
             $table->string('value')->comment('设置值')->nullable();
             $table->timestamps();
         });
diff --git a/public/assets/admin b/public/assets/admin
index ab21b5e..9d13978 160000
--- a/public/assets/admin
+++ b/public/assets/admin
@@ -1 +1 @@
-Subproject commit ab21b5e00e2fd55665bef360cccfd9945557ea0b
+Subproject commit 9d13978a619687bb4c2bc7232857350ad2bf226c