FWIW, i see some chatter on an anti-spam discussion list dating back to March 2013 (happy anniversary) making note of the /24 surrounding these IPs as being highly questionable:
185.18.33.78.in-addr.arpa mailer1.ibwmail.com http://mailer1.ibwmail.com/. 186.18.33.78.in-addr.arpa mailer2.ibwmail.com http://mailer2.ibwmail.com/. 187.18.33.78.in-addr.arpa mailer5.thetradingfloor.co.uk http://mailer5.thetradingfloor.co.uk/. 188.18.33.78.in-addr.arpa mailer4.ibwmail.com http://mailer4.ibwmail.com/.
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On Mar 10, 2015, at 11:50, Anne P. Mitchell, Esq. amitchell@isipp.com wrote:
The domain that is listed is ibwmail.com http://ibwmail.com/; the problem that we are having is that there is no website at all on that domain, nor can we find any spam - anywhere - mentioning the domain. The only clue that we can find is that there is a gambling site that is using the domain as their MX (now, you may be saying that this is a big clue - but given that this is a domain listing, not an IP/MX listing - the two taken together don't add up, and that makes the delisting request process difficult because, for example, there is no message containing the (non-existent) website to include as required in a SURBL delisting request).
This is a sender who is trying to reform their customers' practices, their space, etc... but it's awfully hard to whack anybody with a clue-by-four ("Bad sender! Bad, bad, bad!") when we can't find the puddle they stepped in (to torture a metaphor).