spamd started greylisting in OpenBSD 3.5 (May 2004), in OpenBSD 4.1 onwards, spamd defaults to greylisting mode.
Typical log entries (with -v):
Oct 2 19:55:05 delilah spamd[26905]: (GREY) 83.23.213.115: <gilbert@keyholes.net> -> <wkitp98zpu.fsf@datadok.no> Oct 2 19:55:05 delilah spamd[26905]: 83.23.213.115: disconnected after 0 seconds. Oct 2 19:55:05 delilah spamd[26905]: 83.23.213.115: connected (2/1) Oct 2 19:55:06 delilah spamd[26905]: (GREY) 83.23.213.115: <gilbert@keyholes.net> -> <wkitp98zpu.fsf@datadok.no> Oct 2 19:55:06 delilah spamd[26905]: 83.23.213.115: disconnected after 1 seconds. Oct 2 19:57:07 delilah spamd[26905]: (BLACK) 65.210.185.131: <bounce-3C7E40A4B3@branch15.summer-bargainz.com> -> <adm@dataped.no> Oct 2 19:58:50 delilah spamd[26905]: 65.210.185.131: From: Auto lnsurance Savings <noreply@branch15.summer-bargainz.com> Oct 2 19:58:50 delilah spamd[26905]: 65.210.185.131: Subject: Start SAVlNG M0NEY on Auto lnsurance Oct 2 19:58:50 delilah spamd[26905]: 65.210.185.131: To: adm@dataped.no Oct 2 20:00:05 delilah spamd[26905]: 65.210.185.131: disconnected after 404 seconds. lists: spews1 Oct 2 20:03:48 delilah spamd[26905]: 222.240.6.118: connected (1/0) Oct 2 20:03:48 delilah spamd[26905]: 222.240.6.118: disconnected after 0 seconds.
Newer spamd “stutters” for 10 seconds on connections from unknowns