Re: Massive SPAM Increase {-2.6} {-2.6}

Paul Schmehl <[email protected]> Mon, 09 Oct 2006 17:38:41 -0500
Newsgroups gmane.comp.security.incidents
Message-ID <[email protected]>
--On Monday, October 09, 2006 16:28:24 -0600 Brent Kearney 
<[email protected]> wrote:
>
> Some university campuses maintain strict control over their reverse DNS
> entries, and so departments or on-campus organizations, research
> institutes, etc. that run their own mail servers will have non-matching
> forward and reverse DNS entries on their MX hosts.  Blocking rules like
> this make life difficult for them as well.
>
I would submit to you that any university that doesn't reverse all 
internet-facing hosts needs to hire new people to handle DNS.  It doesn't 
take a brain surgeon to write pointer records.

Having said that, read my response to Tim to see why that's not necessarily 
a problem.  Or better yet, read the link I sent rather than assuming how 
the program works.

> Cases such as these raise the question, if the blocked mail never gets
> into your network, how would you know about the rate of false-positives?
>
Very simple.  Anyone whose email bounces complains to  me personally at a 
known good address on a separate domain.  So far I've had one complaint, 
and I simply adjusted the scoring to overcome the stupidity of his ISP.

Obviously, my brief description wasn't meant to fully explain how 
policyd-weight works.  Read the docs.  It's far from a brute-force tool to 
reject email.

Paul Schmehl ([email protected])
Adjunct Information Security Officer
The University of Texas at Dallas
http://www.utdallas.edu/ir/security/
(unnamed) (application/pkcs7-signature, 4 KB) - not displayed