It's been more than two years since I last wrote about Postini. At the time, the company only offered the service of spam and virus filtering of your e-mail. In the last year or so, Postini has added a range of integrated message management services for both e-mail and IM. If you haven't looked at Postini's offerings lately, it's definitely time to have a look now.

Postini solutions serve more than 35,000 companies and more than 9 million end users. The company processes more than a billion e-mail messages a day, ranking it fourth worldwide (behind only MSN, Yahoo and AOL) in terms of number of messages processed. I'd say the company knows a thing or two about managing e-mail systems.

Something I just learned about Postini is that it operates in a managed service provider mode. That means that you, as a customer, would not have to buy any hardware or software to implement any of Postini's solutions. You simply need to subscribe to the service(s) you want and then change your mail exchanger (MX) record to point toward Postini's servers.

That’s easy enough, but best of all, there's nothing for you to maintain. No virus signature updates. No server patches. No storage systems for legions of spam messages. No hassles! Postini's services operate in the background with virtually no latency and are completely invisible to the senders and recipients of the messages. The only thing they'll see is a vast drop in spam and viruses.

Let's have a look at the various services offered.

* Postini Perimeter Manager provides comprehensive threat prevention for e-mail, and optionally for IM. This is the service that filters out spam, virus, phishing attempts and all that junk that you never want to deal with. Most of this stuff is discarded immediately because it is obviously junk mail. Some of it, however, gets thrown into individual temporary message centers where users can look over their mail and make their own judgment about discarding or accepting messages. I can tell you from experience that there are few false positives on messages, and when they occur, the inbox owner can white list the sender if desired.

If your company is growing dependent on IM, you ought to consider Perimeter Manager for IM. It's very simple to infect a PC via an instant message, so it's better to be safe than sorry.

Linda Musthaler is a principal analyst with Essential Solutions Corporation.