If you are on Exchange, then that is the way it will be. Mixing POP3 accounts and Exchange is never a good idea if you want to avoid mixups like this.
When you us the server to send, it WILL take the default SMTP address.
Marc
If 'something' 'somewhere' gives 'some' error, expect random guesses or no replies at all.
Free Tip: The F1 Key does NOT destroy your PC!