Howtoforge published a guide about retrieving emails from remote servers with getmail

Getmail is a program for retrieving emails from remote servers; it is very similar to fetchmail, but more flexible. For example, it can be configured to deliver mails directly to a Maildir or mbox mailbox without the need for an MTA such as Postfix, but of course it can also pipe the mails through an MTA if you want. Getmail can use so called filters such as SpamAssassin and ClamAV to scan the mails, and you can even tell getmail to delete mails on the original server only after a certain number of days.

Retrieving Emails From Remote Servers With getmail (Debian Etch)