I upgraded to SQLBackupandFTP v11 over the weekend, but have discovered a bug.
I have an SMTP server inside our network, that doesn't require authentication (we use strict IP Address controls for it instead).
So, all of my jobs were set to be empty username/password, and Require authentication unticked.
In order to get my jobs to work correctly, I ended up ticking the auth box, entering a username/password, then unticking it again! Even with the box unticked, it still tried to authenticate!