spamassassin rdns reversedns

Question

Spamassasin gives the following flag on my emails:

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0.8 RDNS_NONE Delivered to internal network by a host with no rDNS

"This test checks to see if there is a reverse DNS entry for the last untrusted relay. Note that this may be done by interpreting information in the relevant Received header - if reverse DNS checks are not performed by the first trusted relay, or if they are not recorded in the Received header, this test will be triggered (regardless of the actual rDNS status)."

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The only ip I can see on my emails are 94.143.11.2 -> which you can reverse dns to trophymanager.com. Google and hotmail have no problems with this - but Spamassassin gives it a flag - what am I missing here?

Answer 1

not sure about spamassassin, but many mail filters / MTAs (postfix for example) only accept the rDNS entry if it's Forward-confirmed. In your case, the forward confirmation does not work:

dig -x 94.143.11.2 +short
man01.trophymanager.com.

but man01.trophymanager.com does not have an A record.

Create an DNS record :

man01.trophymanager.com A 94.143.11.2

and Spamassassin probably won't complain anymore.