Note initial addition of fdm version 1.6 as mail/fdm into The NetBSD
Packages Collection.

fdm is a program to fetch mail and deliver it in various ways
depending on a user-supplied ruleset. Mail may be fetched from
stdin, IMAP or POP3 servers, or from local maildirs, and filtered
based on whether it matches a regexp, its size or age, or the output
of a shell command.  It can be rewritten by an external process,
dropped, left on the server or delivered into maildirs, mboxes, to
a file or pipe, or any combination.

fdm is designed to be lightweight but powerful, with a compact but
clear configuration syntax. It is primarily designed for single-user
uses but may also be configured to deliver mail in a multi-user
setup. In this case, it uses privilege separation to minimise the
amount of code running as the root user.

(seb)