Animail is a multiserver POP3/APOP/IMAP4 (with or
without SSL) mail retrieval utility. It features
an advanced filtering system based on
blacklisting, whitelisting, or a combination of
both. It is possible to send an autoresponse which
prompts people to reply and add themselves to the
'autoaccept' file. It also allows filters based on
regular expressions which match against the email
headers. (If a message is filtered, only the
header is downloaded, not the entire body.)
Combining external filtering programs (e.g.
SpamAssassin or Bogofilter) as message
post-download plugins is also easily acomplished,
thus extending filtering capabilities in an
unlimited way. Available delivery options include
mailbox, maildir, local SMTP, and pipe to a command.