I could only find posts about auto replies when tickets are created. Whenever I'm away from the office or not working, I set an auto reply and corresponding voicemail greeting for my customers that I'm unable to reply until I return. It's very concerning that this basic and essential feature in Jira is lacking. I want my customers to know I'm not replying in a timely matter as I always do because I am away or not working. For now I have a signature template with my current hours, but it's far from ideal. If I want to Resolve a ticket for example, I must Reply to customer first where the template choice is available, insert the signature and enter my comments above it. Send the comment, then Resolve the ticket without a comment.
I do hope there's an option for an auto-reply, otherwise I may need to communicate with my customers regarding the ticket via email.