Has anyone had any luck with this issue yet? I have the same problem with this plugin although I've tried a couple others and the test mail goes through fine so I know I have all the correct info entered.
The reason I'd like to get this plugin to work is because the gravity forms still do not send emails with the other smtp plugins I tried.
In my debug output it's reporting at the end that it has a problem with the email address. Oddly though, that is not the email address I have set and I also updated the wordpress general settings admin email to the smtp email since that was the only place the reported email address had been set. So I can't figure out where it's getting that wrong address.