use jobs to devise emails delivery

app/models/admin_user.rb

@@ -21,4 +21,10 @@
 class AdminUser < ApplicationRecord
   devise :database_authenticatable, :recoverable,
     :rememberable, :validatable
+
+  private
+
+  def send_devise_notification(notification, *args)
+    devise_mailer.send(notification, self, *args).deliver_later
+  end
 end

app/models/user.rb

@@ -51,4 +51,8 @@ class User < ApplicationRecord
   def notification_message
     "🎉 New user: #{email} 🎉"
   end
+
+  def send_devise_notification(notification, *args)
+    devise_mailer.send(notification, self, *args).deliver_later
+  end
 end