24 features that any reliable server side anti-spam solution should have

It is indeed important to have a reliable anti-spam application. Normally there are 2 types of anti-spam (anti-pishing, anti-virus as well) applications that one should rely on: server-side applications and client-side applications. Now, depending on the size of your organization you may choose between a server side solutions or a client side solution. Normally, small companies go for client-side solutions due to flexibility and the fact that they are cheap. However, this doesn't mean that client-side applications are the optimal solution for small businesses. For instance, if you have 10 employees that are currently using they email to send/receive documents, you will realize that a client side-solution is not enough. Not to mention that you will have to purchase 10 licenses. In this case a serve-side application is a more elegant and, most of the times optimal, solution.

Here's a list with the most important features a server-side application should have:

 - Bayesian Analysis - Experimental analysis in which the results are continually revised in light of new evidence on the basis of Bayes' theorem. It mainly involves implication from the administrator that initially needs to "show" the spam filter which messages are being considered as spam and which are not; afterwards she needs to monitor the behavior of the filter and search for misplacements of SPAM messages.
- Downloads new spam signatures - this is a must - periodically updates as spammers are getting more and more inventive
- Keyword checking - the keyword database needs to be periodically updated by the administrator.
- Header checking - we need to see if the header fits with the content of the message; e.g. - if the message says that it comes from a financial services company and the header shows a domain that has nothing to do with the company, than that is SPAM. 
- SPF Support - SPF (Sender Policy Framework) makes it easy to counter most forged "From" addresses in email, and thus helps to counter e-mail spam.
- Identifies directory harvesting - this is a must as well.There is a “silent killer” unleashed by spammers that is threatening to steal your email directory
addresses through what is known as a “directory harvest attack”(DHA). Exchange Servers are especially vulnerable to these type of attacks.
- Automatic whitelist - you need to know your friends and avoid losing important emails.
- 3rd party DNS Blacklist - you always need to check 3rd party databases with blacklisted spammers (DNSes)
- 3rd party URL Blacklist - same as above
- New Senders Sorting
- Listserver
- Users can review their spam
- Customizable policies for groups/individuals
- Installs on Exchange 2000, 2003, 2007 and 2010
- Supports Exchange Anti Spam API and Virus Scanning API
- Supports foreign language SPAM - if you are running your business in an international environment.
- Anti-Phishing
- Blocks spam based on character sets
- Optional Antivirus/Content Security
- Management
- Alerts- Company is Microsoft Gold partner - this is not a must; however, if you are running a Microsoft Server, you should checkout if the software integrates with Microsoft Applications
- Disclaimers
- Logreporting

Visendo Mail Checker Server fulfills all these necessary demands and is targeted at SMBs by its price. No SMB should invest more than needed during these hard financial period.
Try Visendo Mail Checker Server (on visendo.com website) for yourself (it has a trial period of 30 days) and make sure you are aware of the available discounts.
You sould also read the following materials involving Visend Mail checker Server:

- a brief description of the software
- how to integrated Visendo MCS with MS. Exchange 2010 - a screenshot
- Visendo email suite - the optimal email applications for SMBs