On Fri, 04 Aug 2017 12:46:06 -0700 "Ronald F. Guilmette" <rfg@tristatelogic.com> wrote:

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For Abuse purposes... Email Administrators should as a rule not relay/accept emails from IP numbers with no reverse... I do agree completely. However as is made clear by this exact case,

ox <andre@ox.co.za> you wrote: there are enough inbound mail servers still left on this planet that

yes, sadly some of the providers on this list, it is conservatively less than 25% though (aggressive/optimistically 10%), so there is a small/smaller minority still to convert... /* Taking a small break for marketing / advertisement... ************************************************************** If you are reading this thread and you accept emails for relay with no rDNS check, please consider changing your policy :) */

do not follow that rule so as to make it worthwhile for spammers to continue to go to great lengths... even hijacking old & abandoned legacy IPv4 blocks... to get "fresh" IP addresses, even if they can't set up any reverse DNS for those.

In a way, this case shows just how desperate spammers have become in their search for "fresh" IP addres space.

Agree 100% :) Andre