Fetchmail is a full-featured IMAP/POP2/POP3/APOP/KPOP client with easy
configuration, daemon mode, forwarding via SMTP or local MDA, and superior
reply handling.  It is used to handle intermittent email connections by
acting as a coupling that seamlessly batch forwards fetched mail from your
mail server to your local delivery system, allowing you to read your it
with your favourite mail user agent.  Fetchmail also includes useful spam
filtering and multi-user functions.

A typical use of fetchmail is to connect to your ISP's POP3 server,
downloading your mail into the INBOX on your local computer.  You may then
read the mail, offline if you want, using Pine, mutt, or any standard mail
user agent.

Fetchmail is the lineal descendant of and replacement for the old
popclient program.

http://www.tuxedo.org/~esr/fetchmail