Hi, We experienced problems with thunderbird (24.6.0) sending mail bigger than 8MB (Not too big anyway!).
Thunderbird report an error saving the mail in sent (IMAP) folder. The error is a false allarm since the mail is correctly saved. Sometimes happens the mail is saved twice. Never experinced any problem with Outlook Express and LiveMail with any mail size. Anybody else with similar problems? Best regards, Pietro