mail/relaydb 1.7p2 OpenBSD

relaydb is a mail header analyzer that builds a database of IP addresses either known as legitimate senders or spammers.

relaydb doesn't itself classify mails as legitimate or spam; that decision needs to be reached through other means. Neither does relaydb block spam itself. It merely provides a list of IP addresses to block through other means, like spamd(8) and pf(4).

relaydb reads a single mail from stdin, analyzes the Received: header lines and updates blacklist and whitelist counters for each IP address.