Re: DNS blacklists

[Dexter Caldwell <Dexter.Caldwell () FURMAN EDU>]

Mike:
        I'm responding off-list.    We at one point had a problem with blacklists
because they were blocking legitimate mail.  Since you have almost no
control over contacting the blacklist managers and getting anything done
we either had to stop using them or adjust or settings.  One spam
blocklist we like is zen.spamhaus.org.  We also use the barracuda list. 
With the barracudas, we've told it to quaratine on any message coming from
the zen.spamhaus.org  blacklist, that way it never makes it to the inbox
unless the user delivers it manually.  You might consider this approach. 
I know our most vocal users against the false-positives were the folks who
raise money for the campus so it might be a way you can continue to use
the list and keep a reasonable level of protection.  My problem was that
the lists got so bad at one point that I couldn't trust them myself and I
moved to this model a year or so.  Training yoru bayesian databases a
littler better also can help.

Dexter Caldwell
Information Security Administrator
Computing & Information Services
Furman University
3300 Poinsett Hwy
Greenville, SC 29613
email: dexter.caldwell () furman edu
office: 864-294-3566
facsimile: 864-294.3001

The EDUCAUSE Security Constituent Group Listserv
<SECURITY () LISTSERV EDUCAUSE EDU> writes:
> Hi,
> � 
> I was just curious what other campus’ are using in terms of DNS
> blacklist when it comes to email? They are very handy but recently a few
> of them have been the source of some complaints from our users. Currently
> we are using:
> � 
> Rbl-xbl.Spamhaus
> psbl.surriel.com
> cbl.abuseat.org
> bl.spamcop.net
> dnsbl.njabl.org
> Barracudacentral – by default in our barracuda device
> � 
> I know we are probably using more lists than is necessary, but I’m sure
> you all know how cranky people can get if they find a single spam message
> in their inbox.
> � 
> Mike Tupker
> Systems Administrator
> Mount Mercy College
> � 
> �