Somebody else beat us to blogging about it, with far more effect than our puny little efforts.
This spammer has multiple IPs in 18.104.22.168/24. In addition, they rent services under a variety of names from Salesforce Marketing Cloud (ExactTarget), and have their own dedicated block from an Irish provider.
inetnum: 22.214.171.124 - 126.96.36.199 netname: DGPL descr: DGPL country: BB
ET / SMC:
Received: from ba1.mta.exacttarget.com (ba1.mta.exacttarget.com [188.8.131.52]) Received: from mta.email.habcommunity.com (mta.email.habcommunity.com [184.108.40.206]) Received: from mta.email.pro-c.me (mta.email.pro-c.me [220.127.116.11]) Received: from mta.email.pvupdate.com (mta.email.pvupdate.com [18.104.22.168]) Received: from mta.email.opencme.org (mta.email.opencme.org [22.214.171.124]) Received: from mta.email.peercme.com (mta.email.peercme.com [126.96.36.199]) Received: from mta.email.peerviewpress.com (mta.email.peerviewpress.com [188.8.131.52]) Received: from mta.email.peervoice.com (mta.email.peervoice.com [184.108.40.206]) Received: from mta.email.peerquiz.com (mta.email.peerquiz.com [220.127.116.11]) Received: from mta.email.answersincme.com (mta.email.answersincme.com [18.104.22.168]) Received: from mta.email.docguide.com (mta.email.docguide.com [22.214.171.124]) Received: from mta.email.pvchallenges.com (mta.email.pvchallenges.com [126.96.36.199])
Update Dec 8 2015: sorted list of IPs above, added answersincme.com. .71 in the obvious range (pvbriefing.com) is also them.