Duplicate emails in Mail

[mistermingus]

My Mac Mail (4.3) seems to be making multiple copies of emails and attempting to send them thus clogging up my 'sent' box and resulting in 'bandwith exceded' messages. One particular email to a friend, which contains photos, was copied 155 times!!!. This keeps appearing in my 'Recovered Messages' folder and is now preventing my Mail from sending and receiving emails altogether. Has anyone else had this problem? and, if so, any suggestions??