Disabled email notifications if developer_mode is enabled.

app/models/channel.rb

@@ -206,6 +206,11 @@ send via account
 
   def deliver(mail_params, notification = false)
 
+    # ignore notifications in developer mode
+    if notification == true && Setting.get('developer_mode') == true
+      logger.notice "Do not send notification #{mail_params.inspect} because of enabled developer_mode"
+    end
+
     adapter         = options[:adapter]
     adapter_options = options
     if options[:outbound] && options[:outbound][:adapter]

app/models/observer/ticket/article/communicate_email/background_job.rb

@@ -28,9 +28,6 @@ class Observer::Ticket::Article::CommunicateEmail::BackgroundJob
     sender = Ticket::Article::Sender.lookup(id: record.sender_id)
     if sender['name'] == 'System'
       notification = true
-
-      # ignore notifications in developer mode
-      return if Setting.get('developer_mode') == true
     end
 
     # get linked channel and send