Comment 6 for bug 490044

In all honesty, I don't know the details. Looking at the smtplib code in Python 2.6 though, it essentially delegates everything to the socket layer. If the pem/cert files are given, it wraps the socket in an ssl socket, though it only provides a subset of the options available to ssl.wrap_socket(). That's the extent of smtplib's support AFAICT.

Mailman won't support anything the underlying smtplib module doesn't support, so if changes need to happen there, it's best to do that in the context of Python development (though even there, likely nothing will change until Python 3.3 which is a long way off).