spamdyke's reject-missing-sender-mx filter only checks the domain name of the "envelope sender", which is the sender address given in the SMTP protocol. That address is what's used if the message bounces and it is not necessarily the same as the "From address" you see in your mail client. The filter does not check the IP address or rDNS name at all.
It checks for an MX record for the domain or an A record for the machine -- either should suffice. However, due to a bug identified a little while back, some specific domains won't pass the filter because of the way their DNS records are configured. In a nutshell, some administrators (groupon.com) have created DNS records that are technically legal but logically stupid and they tickle a small bug in spamdyke. If this is the same bug, the upcoming version (any day now) will fix it. If you could email the specific server name to me, I'll take a look and let you know if it's the same problem or something new. -- Sam Clippinger On 5/12/11 8:22 AM, Faris Raouf wrote: > Dear all, > > I've been happily using the DENIED_SENDER_NO_MX option for years with no > problems. > > Yesterday, however, 24 hours after finally upgrading to 4.2.0 from a > previous 4.x version (sorry -- not sure which - possibly 4.0.6), I noticed > an oddity in my logs (redacted to protect the innocent). > > Basically an email from some...@sending-domain.com to > u...@local-domain.com was DENIED_SENDER_NO_MX (sending IP's rDNS was > mail.sending-domain.com) > > sending-domain.com DOES have an MX record but mail.sending-domain.com does > not. > > I had always thought that the MX lookup applies to sending-domain.com and > not to the rDNS of the sending IP. My logic is that there are legitimate > reasons why the rDNS on a sending IP might not have an MX record, but no > really good reason why the actual domain in the From line in the envelope > would not have an MX record. > > So....is this some sort of a one-off DNS failure, a misunderstanding on my > part, a bug or none of the above? > > While I'm here, and because I've not posted for years in this group, my > sincere thanks go to Sam for Spamdyke which has to be the most essential > add-on for qmail in existence. It is people like you to tip the balance of > the Internet from lawless and scary to wonderful and magic. > > Thanks, > > Faris. > > > > > _______________________________________________ > spamdyke-users mailing list > spamdyke-users@spamdyke.org > http://www.spamdyke.org/mailman/listinfo/spamdyke-users > _______________________________________________ spamdyke-users mailing list spamdyke-users@spamdyke.org http://www.spamdyke.org/mailman/listinfo/spamdyke-users
