Integrate the freeware SpamAssassin spam-filtering software with Lotus Notes / Domino
It looks like there is a general problem with Lotus Domino 7.0 not properly doing rDNS, which causes the SpamAssassin RDNS_NONE rule to be always triggered. https://issues.apache.org/SpamAssassin/show_bug.cgi?id=5926 For now I recommend setting the score for that rule to 0 in your local.cf file.