diff --git a/app/Http/Controllers/ConversationsController.php b/app/Http/Controllers/ConversationsController.php
index e491b21e..ccfac361 100644
--- a/app/Http/Controllers/ConversationsController.php
+++ b/app/Http/Controllers/ConversationsController.php
@@ -1313,14 +1313,14 @@ class ConversationsController extends Controller
                     $response['msg'] .= __('Action not authorized');
                 }
                 if (!$response['msg']) {
-                    $mailbox_user = $user->mailboxes()->where('mailbox_id', $request->mailbox_id)->first();
+                    $mailbox_user = $user->mailboxesWithSettings()->where('mailbox_id', $request->mailbox_id)->first();
                     if (!$mailbox_user) {
                         // Admin may not be connected to the mailbox yet
                         $user->mailboxes()->attach($request->mailbox_id);
                         // $mailbox_user = new MailboxUser();
                         // $mailbox_user->mailbox_id = $mailbox->id;
                         // $mailbox_user->user_id = $user->id;
-                        $mailbox_user = $user->mailboxes()->where('mailbox_id', $request->mailbox_id)->first();
+                        $mailbox_user = $user->mailboxesWithSettings()->where('mailbox_id', $request->mailbox_id)->first();
                     }
                     $mailbox_user->settings->after_send = $request->value;
                     $mailbox_user->settings->save();
diff --git a/app/Http/Controllers/MailboxesController.php b/app/Http/Controllers/MailboxesController.php
index 50b4c11a..98adee87 100644
--- a/app/Http/Controllers/MailboxesController.php
+++ b/app/Http/Controllers/MailboxesController.php
@@ -156,7 +156,21 @@ class MailboxesController extends Controller
         $users = User::nonDeleted()->where('role', '!=', User::ROLE_ADMIN)->get();
         $users = User::sortUsers($users);
 
-        return view('mailboxes/permissions', ['mailbox' => $mailbox, 'users' => $users, 'mailbox_users' => $mailbox->users]);
+        $admins = User::nonDeleted()
+            ->select(['users.*', 'mailbox_user.hide'])
+            ->leftJoin('mailbox_user', function ($join) use ($mailbox) {
+                $join->on('mailbox_user.user_id', '=', 'users.id');
+                $join->where('mailbox_user.mailbox_id', $mailbox->id);
+            })
+            ->where('role', User::ROLE_ADMIN)->get();
+        $admins = User::sortUsers($admins);
+
+        return view('mailboxes/permissions', [
+            'mailbox' => $mailbox,
+            'users' => $users,
+            'admins' => $admins,
+            'mailbox_users' => $mailbox->users,
+        ]);
     }
 
     /**
@@ -173,6 +187,19 @@ class MailboxesController extends Controller
         $mailbox->users()->sync($request->users);
         $mailbox->syncPersonalFolders($request->users);
 
+        // Save admins settings.
+        $admins = User::nonDeleted()->where('role', User::ROLE_ADMIN)->get();
+        foreach ($admins as $admin) {
+            $mailbox_user = $admin->mailboxesWithSettings()->where('mailbox_id', $id)->first();
+            if (!$mailbox_user) {
+                // Admin may not be connected to the mailbox yet
+                $admin->mailboxes()->attach($id);
+                $mailbox_user = $admin->mailboxesWithSettings()->where('mailbox_id', $id)->first();
+            }
+            $mailbox_user->settings->hide = (isset($request->admins[$admin->id]['hide']) ? (int)$request->admins[$admin->id]['hide'] : false);
+            $mailbox_user->settings->save();
+        }
+
         \Session::flash('flash_success_floating', __('Mailbox permissions saved!'));
 
         return redirect()->route('mailboxes.permissions', ['id' => $id]);
diff --git a/app/Mailbox.php b/app/Mailbox.php
index 2b05053d..fdabbd8b 100644
--- a/app/Mailbox.php
+++ b/app/Mailbox.php
@@ -150,7 +150,12 @@ class Mailbox extends Model
      */
     public function users()
     {
-        return $this->belongsToMany('App\User')->as('settings')->withPivot('after_send');
+        return $this->belongsToMany('App\User');
+    }
+
+    public function usersWithSettings()
+    {
+        return $this->belongsToMany('App\User')->as('settings')->withPivot('after_send')->withPivot('hide');
     }
 
     /**
@@ -363,7 +368,7 @@ class Mailbox extends Model
     {
         $admins = User::where('role', User::ROLE_ADMIN)->select($fields)->remember(\Helper::cacheTime($cache))->get();
 
-        $users = $this->users()->select($fields)->rememberForever()->get()->merge($admins)->unique();
+        $users = $this->users()->select($fields)->remember(\Helper::cacheTime($cache))->get()->merge($admins)->unique();
 
         // Exclude deleted users (better to do it in PHP).
         foreach ($users as $i => $user) {
@@ -374,14 +379,46 @@ class Mailbox extends Model
 
         // Sort by full name
         if ($sort) {
-            $users = $users->sortBy(function ($value, $key) {
-                return $value->getFullName();
-            }, SORT_STRING | SORT_FLAG_CASE);
+            $users = User::sortUsers($users);
         }
 
         return $users;
     }
 
+    public function usersAssignable($cache = true)
+    {
+        // Exclude hidden admins.
+        $mailbox_id = $this->id;
+        $admins = User::select(['users.*', 'mailbox_user.hide'])
+            ->leftJoin('mailbox_user', function ($join) use ($mailbox_id) {
+                $join->on('mailbox_user.user_id', '=', 'users.id');
+                $join->where('mailbox_user.mailbox_id', $mailbox_id);
+            })
+            ->where('role', User::ROLE_ADMIN)
+            ->remember(\Helper::cacheTime($cache))
+            ->get();
+
+        $users = $this->users()->select('users.*')->remember(\Helper::cacheTime($cache))->get()->merge($admins)->unique();
+
+        foreach ($users as $i => $user) {
+            if (!empty($user->hide)) {
+                $users->forget($i);
+            }
+        }
+
+        // Exclude deleted users (better to do it in PHP).
+        foreach ($users as $i => $user) {
+            if ($user->isDeleted()) {
+                $users->forget($i);
+            }
+        }
+
+        // Sort by full name
+        $users = User::sortUsers($users);
+
+        return $users;
+    }
+
     /**
      * Get users IDs who have access to the mailbox.
      */
@@ -498,7 +535,7 @@ class Mailbox extends Model
      */
     public function getUserSettings($user_id)
     {
-        $mailbox_user = $this->users()->where('users.id', $user_id)->first();
+        $mailbox_user = $this->usersWithSettings()->where('users.id', $user_id)->first();
         if ($mailbox_user) {
             return $mailbox_user->settings;
         } else {
@@ -506,6 +543,7 @@ class Mailbox extends Model
             // Create dummy object with default parameters
             $settings = new \StdClass();
             $settings->after_send = MailboxUser::AFTER_SEND_NEXT;
+            $settings->hide = false;
 
             return $settings;
         }
diff --git a/app/User.php b/app/User.php
index d2aa3222..909aedea 100644
--- a/app/User.php
+++ b/app/User.php
@@ -124,7 +124,12 @@ class User extends Authenticatable
      */
     public function mailboxes()
     {
-        return $this->belongsToMany('App\Mailbox')->as('settings')->withPivot('after_send');
+        return $this->belongsToMany('App\Mailbox');
+    }
+
+    public function mailboxesWithSettings()
+    {
+        return $this->belongsToMany('App\Mailbox')->as('settings')->withPivot('after_send')->withPivot('hide');
     }
 
     /**
diff --git a/database/migrations/2020_02_06_103815_add_hide_column_to_mailbox_user_table.php b/database/migrations/2020_02_06_103815_add_hide_column_to_mailbox_user_table.php
new file mode 100644
index 00000000..add8e8d8
--- /dev/null
+++ b/database/migrations/2020_02_06_103815_add_hide_column_to_mailbox_user_table.php
@@ -0,0 +1,33 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+class AddHideColumnToMailboxUserTable extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::table('mailbox_user', function (Blueprint $table) {
+            // Hide admin from Assign list.
+            $table->boolean('hide')->default(false);
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Schema::table('mailbox_user', function (Blueprint $table) {
+            $table->dropColumn('hide');
+        });
+    }
+}
diff --git a/public/css/style.css b/public/css/style.css
index cce3b387..f3685c21 100644
--- a/public/css/style.css
+++ b/public/css/style.css
@@ -2850,6 +2850,10 @@ ul.sidebar-block-list {
     padding-top: 4px;
     padding-bottom: 4px;
 }
+.table-header-nb td,
+.table-header-nb th {
+    border-top: none !important;
+}
 
 /**
  * Modal
diff --git a/resources/views/conversations/editor_bottom_toolbar.blade.php b/resources/views/conversations/editor_bottom_toolbar.blade.php
index f01adf43..a612bc8b 100644
--- a/resources/views/conversations/editor_bottom_toolbar.blade.php
+++ b/resources/views/conversations/editor_bottom_toolbar.blade.php
@@ -22,7 +22,7 @@
             ($conversation->user_id == Auth::user()->id && $mailbox->ticket_assignee != App\Mailbox::TICKET_ASSIGNEE_ANYONE) 
             || (!$conversation->user_id && $mailbox->ticket_assignee == App\Mailbox::TICKET_ASSIGNEE_REPLYING_UNASSIGNED) 
             || $mailbox->ticket_assignee == App\Mailbox::TICKET_ASSIGNEE_REPLYING)data-default="true" selected="selected"@endif>{{ __('Me') }}</option>
-        @foreach ($mailbox->usersHavingAccess() as $user)
+        @foreach ($mailbox->usersAssignable() as $user)
             @if ($user->id != Auth::user()->id)
             	<option value="{{ $user->id }}" @if ($conversation->user_id == $user->id && !in_array($mailbox->ticket_assignee, [ App\Mailbox::TICKET_ASSIGNEE_REPLYING, App\Mailbox::TICKET_ASSIGNEE_ANYONE]))data-default="true" selected="selected"@endif>{{ $user->getFullName() }}</option>
             @endif
diff --git a/resources/views/conversations/view.blade.php b/resources/views/conversations/view.blade.php
index b2c73c26..58a0e819 100644
--- a/resources/views/conversations/view.blade.php
+++ b/resources/views/conversations/view.blade.php
@@ -64,7 +64,7 @@
                                 <ul class="dropdown-menu conv-user">
                                     <li @if (!$conversation->user_id) class="active" @endif><a href="#" data-user_id="-1">{{ __("Anyone") }}</a></li>
                                     <li @if ($conversation->user_id == Auth::user()->id) class="active" @endif><a href="#" data-user_id="{{ Auth::user()->id }}">{{ __("Me") }}</a></li>
-                                    @foreach ($mailbox->usersHavingAccess(true) as $user)
+                                    @foreach ($mailbox->usersAssignable() as $user)
                                         @if ($user->id != Auth::user()->id)
                                             <li @if ($conversation->user_id == $user->id) class="active" @endif><a href="#" data-user_id="{{ $user->id }}">{{ $user->getFullName() }}</a></li>
                                         @endif
diff --git a/resources/views/mailboxes/permissions.blade.php b/resources/views/mailboxes/permissions.blade.php
index 21394205..943176be 100644
--- a/resources/views/mailboxes/permissions.blade.php
+++ b/resources/views/mailboxes/permissions.blade.php
@@ -16,12 +16,13 @@
 
     <div class="container form-container">
         <div class="row">
-            <div class="col-xs-12">
-                <h3> {{ __('Selected Users have access to this mailbox:') }}</h3>
-                <p class="block-help">{{ __('Administrators have access to all mailboxes and are not listed here.') }}</p>
-            </div>
-            <div class="col-xs-12">
-                <form method="POST" action="">
+            <form method="POST" action="">
+                <div class="col-xs-12">
+                    <h3> {{ __('Selected Users have access to this mailbox:') }}</h3>
+                    <p class="block-help">{{ __('Administrators have access to all mailboxes and are not listed here.') }}</p>
+                </div>
+                <div class="col-xs-12">
+                    
                     {{ csrf_field() }}
 
                     <p><a href="javascript:void(0)" class="sel-all">{{ __('all') }}</a> / <a href="javascript:void(0)" class="sel-none">{{ __('none') }}</a></p>
@@ -37,6 +38,28 @@
                             </div>
                         @endforeach
                     </fieldset>
+
+                </div>
+
+                <div class="col-xs-12 margin-top">
+                    <h3> {{ __('Administrators') }}:</h3>
+                </div>
+                <div class="col-md-11 col-lg-9">
+                    
+                    <table class="table">
+                        <tr class="table-header-nb">
+                            <th>&nbsp;</th>
+                            <th class="text-center">{{ __('Hide from Assign list') }}</th>
+                        </tr>
+                        <fieldset id="permissions-fields">
+                            @foreach ($admins as $admin)
+                                <tr>
+                                    <td>{{ $admin->getFullName() }}</td>
+                                    <td class="text-center"><input type="checkbox" name="admins[{{ $admin->id }}][hide]" value="1" @if (!empty($admin->hide)) checked="checked" @endif></td>
+                                </tr>
+                            @endforeach
+                        </fieldset>
+                    </table>
                     <div class="form-group margin-top">
                         
                         <button type="submit" class="btn btn-primary">
@@ -44,8 +67,8 @@
                         </button>
                     
                     </div>
-                </form>
-            </div>
+                </div>
+            </form>
         </div>
     </div>
 @endsection