[Dovecot] 9GB of messages in /tmp

Hello,

Well, I have a brain-dead user (using Thunderbird 2.0.0.14) who just won't listen when I tell them not to try to move 5000+ messages at one time (or if deleting, bypass the Trash), and they managed to royally screw up their maildirs...

I have two problems...

1. The /tmp directory has 9+GB in it... can I just rm tmp/* on that directory without making this problem worse?

and

2. One of the directories they were moving now has 5 copies of a whole bunch of messages...

I'm very dangerous when it comes to command-line work beyond really basic stuff, and my scripting skills are less than inspiring...

Is there a relatively safe command-line way of finding all messages that have more than one instance, and deleting all but the last instance?

Tia...

--

Best regards,

Charles