Lets show you how to enable SSL option in outlook while setting up e-mail account. Usually the SMTP, IMAP/POP3 ports in PCI restricted servers should be secured.
SSL ports for SMTP, IMAP/POP3
The ports used by secure email are:
Make sure that the hostname you provide at the time of mail client setup should be server’s hostname, if you would like to use your own domain name as hostname, the domain name should contain a valid SSL.
Before setting up the e-mail account in outlook, you must have setup the mail account via your site’s cPanel, once it is done you can go ahead with mail client configuration.