IMAP (1986) — the Internet Message Access Protocol — is a popular protocol for e-mail retrieval, transmission, and synchronization.
afallen is a cronjob-driven, OfflineIMAP-dependent, and (optionally) Bogofilter-dependent Perl module for synchronizing, filtering, sorting, and spam-marking Maildir-style e-mail from one or several remote, IMAP-enabled e-mail servers onto the local e-mail client — your local machine. See: