Email protocols explained :
For those who want a simple explanation for e-mail ports and protocols here it is :
PORT 25 TCP : SMTP
PORT 110 TCP : POP3
Port 143 TCP : IMAP
Port 465 TCP : SMTPS (SSL)
Port 587 TCP : alternate SMTP, sometimes used if your ISP blocks port 25
Port 993 TCP : IMAPS (SSL)
Port 995 TCP : POP3S / POP3 TLS/SSL
TLS can be used on any port.
TLS it’s backwards compatible with older versions of SSL.
TLS it’s open stadandard, and it’s the succesor of SSL.
SSL has it’s own ports : 465 or 993.
Examples of use :
Gmail.com :
SMTP 465 SSL / TLS
IMAP 993 SSL / TLS