Guys! You see what The Bat! has done!!! :( As I use GMail IMAP, this is where the problem is. This also happened in the past. And is back again (although I deleted my account, recreated it from scratch and synced 100% yesterday).
So, this is what happens: 1. I create a message. 2. Put it in Outbox (Outbox is a local folder on my PC). 3. I hit send & receive. 4. I see the progress and think the message has been sent 100%. 5. I don't look in GMail Outbox, as I'm sure the mail has been sent. And Outbox is off the screen, as I have a long list of folders, so I can't see that Outbox in not empty! 5. But actually, a copy is left in Outbox. So, each time I hit F11 to send a new mail (from a different account), this copy is also being re-sent!
________________________________________________________ Current beta is 4.0.39.38 | 'Using TBBETA' information: http://www.silverstones.com/thebat/TBUDLInfo.html