Anyhow, can Dovecot be used as a mail filter/proxy? Basically what I would be interested in doing is have dovecot download my email from my ISP accounts. Then I would set my client to point to my internal server. Is this possible? Worthwhile?
As others have suggested, fetchmail downloads mail from other servers and redelivers it using the local MTA (eg. postfix or sendmail). Dovecot serves mail already on the server to POP3/IMAP clients.