[Mimedefang] $RelayHostname not matchingsendmail's Receivedheader?
John Rudd
john at rudd.cc
Wed Dec 6 14:32:57 EST 2006
Michael Sims wrote:
> John Rudd wrote:
>> Michael Sims wrote:
>>> No biggie, my Net::DNS solution is working fine so I'll stick with
>>> that for now.
>> What exactly is it that you're trying to do?
>
> Get the PTR for the connecting relay, even if the forward and reverse lookups don't match. Apparently $RelayHostname only contains the PTR if they do match. Currently I'm checking for this and using Net::DNS to get the PTR myself if necessary...
>
That part I could figure out.
I meant "what are trying to accomplish once you have that PTR record"?
Are you going to do something similar to what my Botnet SpamAssassin
plugin does? Botnet was based on code I had actually written into my
mimedefang-filter ... and I could share that code with anyone trying to
produce the same result.
Botnet looks to verify that:
a) the relay has a PTR record at all
b) optional: the hostname in the PTR record resolves, and resolves back
to the IP address that you're talking to
c) the hostname doesn't contain 2 or more octets of its IP address in
hex or decimal form
d) the hostname doesn't contain certain "client like" keywords (dsl,
dynamic, dialup, etc.)
e) (in Botnet, but not in my mimedefang version) will exempt c & d if
the hostname does contain certain "sever like" keywords.
Right now, I use Botnet instead of my old mimedefang code.
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