On 8/22/2014 3:55 PM, Kevin Miller wrote:
I was looking at the output from logdigest on my egress mail server
(smtp.ci.juneau.ak.us) and came across these:
System Error Messages:
aboutres.net. config error: mail loops back to me (MX problem?): 1 Time(s)
flylib.net. config error: mail loops back to me (MX problem?): 1 Time(s)
agesub.net. config error: mail loops back to me (MX problem?): 1 Time(s)
midpoint.agesub.net. config error: mail loops back to me (MX problem?): 1
Time(s)
despoina.flylib.net. config error: mail loops back to me (MX problem?): 1
Time(s)
lectisternium.aboutres.net. config error: mail loops back to me (MX
problem?): 1 Time(s)
And sure enough, the sleazy spammers are putting a loopback address in their
DNS for the domain,
mkm@mxg:/etc/mail> host lectisternium.aboutres.net
lectisternium.aboutres.net has address 127.0.0.1
Is anyone else seeing these? What's the best way to block a server for which
DNS returns a loopback address? I'd think at the MTA, but a rule might be
effective too.
I wrote a perl module just for this issue called valid mx. I then hook
into it with MIMEDefang.
http://search.cpan.org/~kmcgrail/Net-validMX-2.2.0/lib/Net/validMX.pm
though I have a newer version I should upload.
Regards,
KAM
