Question:

A user replied to a ticket that had been resolved. I'd expected their message to be added to the ticket thread, but instead, a new ticket was created. What's going on?

Answer:

Check that the user did not reply from a different email address that is not associated with their account in Deskpro.

If they were using the same address, the user probably did not have permission to re-open a resolved ticket.

Under Admin > CRM > Usergroups, hover over the usergroup that the user belongs to and click the Pencil edit button.

Here you can check the settings for the Can re-open resolved tickets permission.

If none of the usergroups in your helpdesk grant permission to re-open resolved tickets, replies on resolved tickets may be rejected or accepted as a new ticket.