milter-greylist

Greylist milter for sendmail

Install

All systems
curl cmd.cat/milter-greylist.sh
Debian Debian
apt-get install milter-greylist
Ubuntu
apt-get install milter-greylist
Alpine
apk add milter-greylist
image/svg+xml Kali Linux
apt-get install milter-greylist
Fedora
dnf install milter-greylist
Windows (WSL2)
sudo apt-get update sudo apt-get install milter-greylist
Raspbian
apt-get install milter-greylist
Docker
docker run cmd.cat/milter-greylist milter-greylist powered by Commando

milter-greylist

Greylist milter for sendmail

milter-greylist is a stand-alone milter written in C that implements the greylist filtering method, as proposed by Evan Harris. Greylisting works by assuming that unlike legitimate MTA, spam engines will not retry sending their junk mail on a temporary error. The filter will always temporarily reject mail on a first attempt, and to accept it after some time has elapsed. If spammers ever try to resend rejected messages, we can assume they will not stay idle between the two sends (if they do, the spam problem would just be solved). Odds are good that the spammer will send a mail to an honey pot address and get blacklisted in several real-time distributed black list before the second attempt.