I have configured postfix, courier on EC2 which is having Ubuntu 12. The necessary port's are opened SMTP, IMAP, POP3.
Installed and configured postfixadmin. Added domain and some mail boxes.
I am able to send mail from that admin panel to any email address.
But not able to log in to any email account using outlook. It gives can't established secured, unsecured connection error. If outlook configured manually using POP3 or IMAP it gives error you mail server rejected your login details. -ERR login failed.
I think something has to be done at server side to enable connection or something like enabling port from console but don't know.