I'm not exactly sure what you're describing here. MX records are supposed to be names, not IP addresses. spamdyke's "reject-missing-sender-mx" option already checks for the existence of an MX record, then tries to resolve each name to an IP address. I'm not sure I would see the point in trying to resolve each IP address' reverse DNS name; reverse DNS is generally required for IP addresses where email connections originate, not where they terminate. In other words, outgoing servers should have valid rDNS, but incoming servers aren't required to have it -- if a server is willing to accept email, that's not necessarily an indication it's a spam source.
Some DNS administrators mistakenly set their MX records to contain IP addresses. This is technically illegal, but spamdyke honors them as valid with no further checking. So anyway, I think I'm misunderstanding what you're asking for. :) -- Sam Clippinger On Oct 3, 2013, at 7:16 PM, Eric Shubert wrote: > I don't know if this has come up before, but it just came to my > attention that there are some mail servers which check rDNS of domain MX > records before accepting emails. I don't believe spamdyke does this. > > Is this a total waste, or would it perhaps catch some spammers? > > Some domains have many MX records. I wonder if all MXs are checked, or > only the highest priority? > > Seems like a bit of a waste of resources to me. Any thoughts about this? > > (I'd certainly prefer to see SPF implemented than MX rDNS checking!) > > Thanks Sam (and everyone). > > -- > -Eric 'shubes' > > _______________________________________________ > spamdyke-users mailing list > [email protected] > http://www.spamdyke.org/mailman/listinfo/spamdyke-users _______________________________________________ spamdyke-users mailing list [email protected] http://www.spamdyke.org/mailman/listinfo/spamdyke-users
