126.96.36.199/16 [belongs to Nobis Technology](http://www.tcpiputils.com/browse/ip-address/188.8.131.52).
We've had spam from at least 20 different IPs in this range over the course of a year. We've had them blocked for a month, then three months or so. I think it's time to block them for a year.
Their [website](http://nobistech.net/) says they are involved with "very lucrative Internet services". I wonder if spamming is one of these lucrative services.