How?
osTicket doesn't not do this by default (as responses to closed tickets re-opens them). So you must have changed the setting to make it not do that.
Go to Admin panel -> Manage -> Lists -> Ticket Statuses -> Closed Click on Item Properties tab check "Allow reopen" Click Save.
Hello, yes, I know about that setting. I don't want customers to keep re-opening ticket, but I also don't want their replies to open new ticket when I close ticket, I already let them know their replies will be ignored with a "Canned Response"
Well then you have a choice to make.
You can either deal with 'Thank you" emails re-opening tickets, or extra tickets when people respond to closed tickets.
Maybe I should learn PHP, there should be the possibility to edit the fetching code when it detects ticket's thread status as closed to not create the ticket.
That is of course a third option. 🙂