Add SMTPS/STARTLS support
This MR adds SMTPS and STARTTLS support. Fixes #252 (closed).
The tests use a self-signed certificate for localhost with these fields:
Subject: C = US, ST = MA, O = Mailman test certificate, CN = localhost
I used the values for FSF, since Mailman is a GNU project and nothing better came to mind.
Edited by J08nY