We're having a problem with a specific user who opens a lot of tickets sending us emails. The new emails she sends instead of generating a new ticket generates a comment on an older ticket already closed.
The title and body follow a pattern but are never the same.
For example: four emails happened to be registered as comments on an older ticket, I deleted this ticket to see how it behaved and when she sent an emails again, the first registered a ticket and the other came as a comment on this ticket.
Sorry if I wasn't clear, if you need any more information let me know.