On 2016-02-27 9:59 PM, Suresh Ramasubramanian wrote: > A domain with a null mx may well originate email but will absolutely not > receive email - so mail gets trashed at your end as well without staying > endlessly on your mall queues > > You can possibly correlate that mx with the behavior of domains that are > sending you mail.. Though a domain rather than IP bl may make sense. >
Sorry, I realized after I sent that I needed to clarify that what I'm observing are MTAs attempting to deliver email to addresses at IP of the A record for the domain, ignoring the presence of its NULL MX. So the originating MTAs are ignoring the NULL MX and attempting to deliver to the A hostname, leading me to surmise they are spambots or zombies. - mark > --srs > >> On 28-Feb-2016, at 8:07 AM, Mark Jeftovic <mar...@easydns.com> wrote: >> >> >> What is an MTA supposed to do with a message addressed to a domain with >> a NULL MX? >> >> RFC 7505 talks about domains with a NULL MX should not originate email >> (in their sender envelopes, etc) but what about the converse? >> >> I'm looking at some logs and seeing attempts to deliver email to lots of >> domains with NULL MX enabled (that have been so for years) and wondering >> if I can safely mine these logs and add all the originating MTA IPs to >> an internal RBL. >> >> I think I can. I think I will. >> >> - mark >> >> -- >> Mark Jeftovic, Founder & CEO, easyDNS Technologies Inc. >> Company Website: http://easydns.com >> Read my blog: http://markable.com >> +1-416-535-8672 ext 225 >> >> _______________________________________________ >> mailop mailing list >> mailop@mailop.org >> https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop -- Mark Jeftovic, Founder & CEO, easyDNS Technologies Inc. Company Website: http://easydns.com Read my blog: http://markable.com +1-416-535-8672 ext 225 _______________________________________________ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
