First my apologies to all people who come back here day after day and wonder why there’s no action on Grynx. Well, try working 10 hours a day, studying for your MCSE every evening and then take care of your family as well. I’m simply not allowed into my garage any more
Hopefully this will change in the next coming months – but I make no promises.

In September 2007 I published an little application of mine called Greylist. At that stage Greylist was a bit unpolished and rough but it did evolve during the next coming months whenever I could stick a bit of time into it.

Today I published v1.3 which now is more of a grownup and handles both stress and problems in a more correct way.
Some interesting statistics about the artice: Over 8500 people has read the article in the last three months and it has been downloaded over 1500 since end November.
Not bad for me that didn’t have a clue about programming 6 months ago. Pat Pat on my own back

Since I have had a lot of problems with false positives with the black lists that I’m using on my Exchange 2003 server I started looking into another way of filtering spam…
The problem with this is that there doesn’t seem to be any free products out there for Exchange and as I don’t want to set up a Linux box ( yet another box in the rack ) I decided to write one myself…

Features of today includes selective blocking (sender ip and/or sender address and/or recipient address), stores data in a access db or in MS SQL, the database can be shared across the enterprise, automatic pruning. In the latest version I added functionality for different actions upon grey listing a recipient as well as custom server messages.
And in many scenarios it block up to 98% of all spam!!

If you’ve read this far and don’t have a clue about what I’m talking about then let me say this:
– Grey listing temporarily blocks an email in an attempt to filter out spam servers.
– Greylist (the program I wrote) only runs on Exchange 2000 and 2003.

If you’re an Exchange admin and you have problems with spam then be sure to check out my implementation Greylist – freeware Grey list for Exchange

Greylist is simply a greylist program for Exchange 2003 ( should work on 2000 ) which will delay incoming mail for a couple of minutes. In my environment it blocks 98% of all spam and so far it hasn’t blocked a single ‘good’ email.
And as I like the whole idea of open source, I’m publishing it just like that – for free. Or rather freeware.

I wrote this as I couldn’t find any free grey list programs out there. Lots and lots for free for Linux, but only commercial products for Exchange.

Link: Greylist v1.0 for Exchange