Grey listing is a wonderful spam filtering technique, which uses a behavior trick: spammers never resend a message when they get a temporary error, whereas real MTA do. The idea is to refuse any mail on first attempt, and accept it after some time has elapsed. milter-greylist is a stand-alone milter written in C that implement grey listing. It has been reported as efficient and easy to setup by a large number of system administrators.
Binary packages can be installed with the high-level tool pkgin (which can be installed with pkg_add) or pkg_add(1) (installed by default). The NetBSD packages collection is also designed to permit easy installation from source.
The pkg_admin audit command locates any installed package which has been mentioned in security advisories as having vulnerabilities.
Please note the vulnerabilities database might not be fully accurate, and not every bug is exploitable with every configuration.
Problem reports, updates or suggestions for this package should be reported with send-pr.