Postgrey
Installation pacman -S postgrey
Activate configuration cp /usr/lib/systemd/system/postgrey.service /etc/systemd/system/
Add to Postfix configuration /etc/postfix/main.cf
smtpd_recipient_restrictions = check_policy_service inet:127.0.0.1:10030 Add automated whitelist /etc/systemd/system/postgrey.service
ExecStart=/usr/bin/postgrey --inet=127.0.0.1:10030 \ --pidfile=/run/postgrey/postgrey.pid \ --group=postgrey --user=postgrey \ --daemonize \ --greylist-text="Greylisted for %%s seconds" \ --auto-whitelist-clients=5 systemctl deamon-reload
systemctl restart postgrey