[Greylist-users] some comments on spamd

[Graham Toal]

A final update on my saga of building a greylist server using spamd...

It has been live in front of the University of Texas Pan American for
two weeks now.  I am using greylisting plus a small list of blacklisted
IPs which I built myself by observing the traffic hitting the greylist
and then checking each IP against other blacklists to make sure they
were indeed bad networks.

We have cut down incoming spam by 90%.  We now get one spam per good
mail instead of 10 spams per good mail.  We reject over 80,000
*connections* per day from spammers, and presumably far more actual
spam deliveries than than (as many of the connections would have sent
to every user on campus - 15,000+)

The unsolicited emails from campus users have been tremendous.

I am so impressed.  I knew greylisting would be a good tool in the
arsenal of anti-spam measures, but I never guessed it would overnight
become our *primary* tool.  Can't recommend it enough - if you've been
thinking of taking the plunge and have been put off by the complexity
of setting it up, go ahead and try it.

My notes on setting it up are here, if they help anyone:
  http://wiki.utpa.edu/InfoSec/GreyListing

However I had some constraints that made it necessary for me to use
spamd in a non-standard config.  If you are able to set it up the
way that is recommended - as a transparent bridge - I'd suggest
doing that instead.  It seems less complicated that way.

Thank you everyone (and esp. Mark Pecaut) for your help in getting
me online with this.  It has been greatly appreciated by many of our
users, some of whom have gone from 150 spams per day to a dozen.

Graham