I posted a merge function on this thread http://forum.osticket.com/d/discussion//merge-join-two-and-more-ticket-into-oneNothing on unmerge though.I had a merge on mail function in 1.6 release that I'll likely port to 1.9 shortly too. It worked such that the same user (aka email) with the same title, automatically merged into an existing open ticket. If the ticket was closed however, a new ticket was generated.D.