[Mailman-Users] corporate spam filter operation

[Brad Knowles]

On 3/21/08, Matt Morgan wrote:

>  Are there corporate, enterprise spam-killing services that work on a
>  user-by-user basis, rather than a message-by-message basis? For example,
>  where the same message, sent to a few different people, might be rejected as
>  spam for one recipient but not others?

You mean commercial systems that would be suitable for use in an 
Enterprise environment?  Not that I am aware of.

There are some tools like SpamAssassin that can be configured to have 
a database that stores the settings of an individual user and then 
applies those to the incoming messages, but that's non-trivial to set 
up and manage.  It can be done, but it takes some work, and there's 
definitely a cost that you end up paying in terms of higher 
administrative overhead in managing that system.

And procmail can be configured to run rules for processing the mail 
for each user as it is being delivered to their mailbox, and take 
various different actions with the message (file it to a separate 
folder, throw it away, run other programs, reject it, etc...).


Typical anti-spam appliances that I've seen would be like things from 
Barracuda or IronPort, and I don't know of any such appliances like 
this that have these kinds of features.

Personally, I would recommend avoiding the Barracuda appliances, 
since they come programmed by default to do some pretty stupid 
things, and they don't scale that well.  I've heard better things 
about the IronPorts, however.

>  What I'm seeing is that often, about 50% of the messages to a domain are
>  rejected. It seems like too many for them all to just be bad, old addresses
>  (although that's possible--this list has not been updated for a while), but
>  too few for them to have been rejected by spam filters.

Ahh, now there you could definitely be caught by people on the other 
end who are running into those SpamAssassin or procmail-type per-user 
filters.

-- 
Brad Knowles <brad at shub-internet.org>
LinkedIn Profile: <http://tinyurl.com/y8kpxu>