I'm now looking to ensure that my server can service the following e-mail protocols on the indicated ports on my CentOS 6.2 x64 server: POP Ports POP3, if available use STARTTLS - Port 110 POP3s, SSL is required - Port 995 SMTP Ports SMTP, if available use STARTTLS - Port 25 (note some ISPs block port 25) SMTPs, SSL is required - Port 587 IMAP Ports IMAP, if available use STARTTLS - Port 143 IMAP4s, SSL is required - Port 993 I note that Sections 10 and 11 in The Perfect Server - CentOS 6.2 x86_64 With Apache2 [ISPConfig 3] - Page 4 deal with installing mail services, but no mention is made at all with respect to the above protocols and ports. I do see Section 11, Postfix With SMTP-AUTH And TLS, in The Perfect Server - CentOS 6.0 x86_64 [ISPConfig 2] - Page 4. This section does talk about some of these things, but it seems incomplete with respect to the above protocols and ports. Also, is this information correct for the CentOS 6.2 Perfect Server document? Can someone help identify what is needed to have a CentOS 6.2 x64 server support the above protocols and ports? Please note that I have an SSL certificate for the mail domain (e.g., mail.myserver.com).