Is anyone familiar with this mail program?

My secretary insists on using this program at work and for the second time she has managed to really lock up the program. Somhow she tried to send a 200mb file to someone and it is stuck in the program and won't send. Even worse it is locking up the system and causing every other program to run real slow. The mail is in the outgoing folder but because of the size it won't send and I can't even delete it. Is there a way to find the file outside of the actual outlook program and manually delete it? OR is there any other way to fix the problem? For now I set her up to use Outlook Express but she likes all the features the other program has that Express doesn't.

Any help would really be great.