I spent the day working on real work, but did manage to steal a few minutes this evening to configure postfix and stunnel4 on my laptop to get outbound mail working from sendmail compatible apps. Apparently postfix doesn’t do smtps, so I used stunnel to get the SSL layer.
If there’s one thing that will save you an hour of head-scratching, it’s this: remember to update the hostname in your password file when you switch to using a tunnel. I left the original external SMTP server in there, and was banging my head against the wall until I finally realized that postfix would now be looking for a localhost entry instead.