Issues with Auto Email Responses for New "Case Category" Lookup Values

Hello everyone! ,

 I've added new values to "Case category" Lookup, but when i choose one of them when setting up "List of Mailboxes for case registration" it doesn't send auto email response or any email in stage transition like "Service request" or "Incident" which already exists. 

so to sum up there is a problem with sending auto email in case i choose the new categories that i added to the lookup. (auto case registration works perfectly)

so does anyone is familiar with this problem so he/she can help me to solve it? 

and in case of manual registration, the emails is being generated as a drafts in the conversation tab, is there a way to not make it as draft and send it automatically like case registration by email?

thank you for your time.