Mail crashing questions

10.4.9...Ever since my mother sent a 25 mb file in her email, Apple mail has not been right since. We've seen it launch itself after a restart, as well as crashing all the time.

So, I was going to delete the .plist... but I wondered what happens to the mailboxes when you do this. In mail when you delete the plist, you've got to set up your account from scratch. Should I back up the mailboxes to another spot and then import them, or leave them where they are and hope mail figures out they belong to the new account?

Alternately, if anybody has a better idea how to resolve this problem, I'm all ears. Thanks.

Thanks for your help... yeah it's my mom's computer so I couldn't check the version... she actually is on 10.4.11. I went over there last night and she said it seems fine now. I won't be over there to check for another week.

For all intents and purposes, the message seems to have been deleted from the sent mail (in the app anyway) I forgot I could even see the 25 mb file through the finder. I am used to troubleshooting Panther mail. I guess I should check that next time I'm over.

The other side effect I noticed was that outgoing mail was slow as nuts, and she doesn't seem to get the spinny thing showing it's downloading mail when she hits 'get mail'. I wonder if the file messed up the server mailbox? (It's pop)

Anyway, no crashes for now I guess. Thanks.