[expert] login based smtp/ ssmtp

[Nima S. Panahi]

Hi,
I run a webmail and email system. The only access I want to give is secure
SSL type. I have already setup a SSL based imap, pop3, and webmail system.
However, for the simap and pop3s users, they need smtp . My users are all
over the world and I cannot select access based on network, therefore I
want to  have an SMTP server that allows usage if people login. I also
want this  smtp server to be ssmtp (over SSL). I am using Postfix on the
system, any  help or direction pointing will be great. Thanks!