I installed 0.3 and during configuration via the Installer module I couldn't get the SMTP test to send an email, it was really confusing as to why as I knew the details were correct.
Anyway after a while I just ignored the error and completed the remaining configuration. It's working perfectly and I can successfully send mail using the SMTP details I configured.
Whilst looking through my reject.log file for Exim I noticed the cause for the failure, the test email doesn't add a Date header.
I've configured my mail server to be quite strict and therefore requires the Date header to meet RFC standards.
Normal operation adds all the correct headers.
I don't recall this being a problem on previous versions.