SEMblog

A common question that keeps coming up on forums and similar sites is "What is the best anti spam solution?"

Unfortunately there is no single answer to this question.
I usually respond with something like "What is the best car, best house, best wife?"

The only answer is that the best product is the one that works for you.
On most forums, most of the posters will have experience with one or two products, so will post that product X has worked well for them.
Someone else may well post and say that product X sucked and product Y was the best solution. Then another person will say, don't bother with a product, outsource it to service Z.

On my home network I have had good experience with Vamsoft ORF, but when I tried it on another site it was unsuccessful. I also tried GFI Mail Essentials at home, found it's performance wasn't great for me. However at another client it has been very successful.

When it comes to looking at antispam solutions, the key metric should not be how much spam does it remove, but how much legitimate email it blocks. If the product is stopping email you want from being delivered, then you need to look at a different product.

I have personal experience with this with a client a few years ago.

The client was a large finance company. They did loans and mortgages through brokers, many of whom used AOL and similar accounts.  (It will surprise you how many of the very small businesses like one man band brokers still do).
They have a requirement for zero false positives - because a single false positive could mean the loss of many thousands of pounds of business.
We evaluated every product on the market, from open source to high end commercial and out sourced solutions. The requirement was very strict - and every product failed because they were all blocking one or two messages a week that were legitimate.
It actually reached the point where we started to put a plan together to hire IT contractors whose sole responsibility was to go through the quarantine email manually, as it was worked out that they would only have to save one email every six months to make it worth while to the company. However in the end, one of the out sourced providers built a custom solution for them so that the management could be handed off.
 
The point I am trying to get across is that asking people what works for them and then using that for a buying decision isn't really a good idea. It does not allow you to bypass the evaluation period. Everyone knows that users don't like spam and no doubt as the administrator of the server you will be under pressure to find a solution that works. However purchasing in haste may actually end up costing your company money.

Most of the major products have evaluation versions you can download. Install them and run them in report only mode. See what it would catch. If you decide to start block messages, then quarantine them first so you can check for false positives.

You could find that the product that someone posts saying "We tried product X and it didn't catch a thing" actually works very well for you.