wip/relaydb 1.7 NetBSD

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).