The qmail Handbook

getmail is a POP3 client written in Python. It retrieves messages from a Post Office Protocol version 3 (POP3) server and delivers them locally to maildir or mbox mailboxes or programs.

Chapter 10, "Serving Mailboxes," covers installing, configuring, and using getmail.

getmail was written by Charles Cazabon, who maintains a Web page for it (http://www.qcc.sk.ca/~charlesc/software/getmail-2.0/).