Rule for DNS MX Check

Matt Kettler mkettler at
Mon Nov 6 21:01:15 GMT 2006

Side note for Max:

While you're at it, you might want fix your own DNS records:

Received: from ( [] (may be
	forged)) reverse DNS resolves as "", but that name has no
forward resolution. This is strictly invalid, as all records returned by
resolving a PTR MUST resolve back to the same IP.

(note: this is different than making assuptions about HELO strings)

# host domain name pointer domain name pointer

# host

Furthermore, the other record does resolve, but to a different IP address:

# host has address


See RFC 1912 section 2.1

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