What ports are used for email?
TCP port 25, TCP port 110, and TCP port 143.
(SMTP, POP3, and IMAP4)
TCP is an acronym for Transport Control Protocol.
SMTP is an acronym for Simple Mail Transfer Protocol and it uses TCP port 25.
POP is an acronym for Post Office Protocol and it uses TCP port 110.
IMAP is an acronym for Internet Message Access Protocol and it uses TCP port 143.