See man 1 policyd-spf for additional documentation. Installing ---------- This package must be integrated with Postfix to be effective: 1. Add the following to /etc/postfix/master.cf: policyd-spf unix - n n - 0 spawn user=policyd-spf argv=/usr/bin/policyd-spf 2. Configure the Postfix policy service in /etc/postfix/main.cf: smtpd_recipient_restrictions = ... reject_unauth_destination check_policy_service unix:private/policyd-spf ... policyd-spf_time_limit = 3600 NOTE: Specify check_policy_service AFTER reject_unauth_destination or else your system can become an open relay. 3. Reload Postfix.