GreyList Sendmail milter is a lightweight, fast, and reliable Sendmail
milter that implements the Greylisting antispam technology. It has a
flexible configuration and a very effective Greylisting algorithm on
the base of this tuple: sender's IP address (Class C subnet), envelope
sender address, and envelope recipient address. It's a light alternative
to the milter-greylist, graymilter, and milter-gris milters.
