That is not currently possible. As you have discovered, you can have it append their response to the existing ticket and reopen it, or you can have it open a new ticket. There is not a way to configure it that has it "ignore" a response from a user. You could probably alter the code in some way to append and NOT reopen the ticket, but you cannot configure it that way in the UI.In my experience, there really isn't a good way to tell if the ticket is just a thank you, or a new issue (that they are sending in the same thread as the previous), so we would not want the system to just disregard an email from a user anyway.Is it annoying to have to reclose a ticket that was opened by a thank you? Yes. Would you rather have them pissed off because what they sent was not a thank you, but a completely different request that they were just replying on the same thread, and it was just ignored? Probably not.