For countering viruses, we have desktop and server-side anti-virus software. While this has mitigated the virus bane for many, there are a couple of limitations: the software needs to be updated regularly (many computer in countries like India and China use pirated software on the desktop, which may not have the latest updates to keep out the newest viruses), and there is a time lag between the virus being detected and the cure being made available. The time delay means that even a single infected computer can cause significant damage to a corporate network.
Spam is different. It is incessant. There is a continuous battle of wits as spam marketing companies try to outwit the spam filters that users are setting up on the desktop and server-side. InfoWorld uses SpamAssassin: [It] is easy to install and customize, with a basic interface for adding domains and e-mail addresses to blacklists and white lists. To do its work, SpamAssassin uses word and phrase matching, real-time blocking lists, and on-the-fly spam-reporting features. Each e-mail is assigned a score depending on the detected level of spam probability. By default, SpamAssassin flags a message as spam if the score is above five. We actually use a score of six for the [SPAM] flag to be added to a message subject line and a score over 10 for it to be automatically moved to a [separate] folder.
For Outlook users, Jon Udell recommends SpamBayes:
The commercial e-mail that I want to receive (or reject) will differ from the ones you want (and don’t want) according to our interests and tastes. A filter that works on behalf of a large group, such as SpamAssassin, which checks and often rewrites my infoworld.com mail, or CloudMark’s SpamNet (formerly Vipul’s Razor), which collaboratively builds a database of spam signatures, will typically agree with SpamBayes on what I call the Supreme Court definition of spam: You know it when you see it. What sets SpamBayes apart is its ability to learn, by observing your behavior, which messages you do want to see, and the ones you don’t.
SpamBayes appears as a toolbar item called Anti-Spam. To use the add-in effectively, you’ll need to point it to a pile of ham. These messages may simply be the contents of your inbox if you keep it squeaky clean. But they can also live in other folders. That’s great news, because I use Outlook’s filters aggressively to route messages from known correspondents to folders.
You’ll also need to point SpamBayes to a big pile of spam. In my case, that folder was called NotToMe, where an Outlook filter has long been accumulating messages that are neither To: nor CC: my primary e-mail addresses. This simple rule is so effective at filtering spam that it was my sole defense until InfoWorld installed SpamAssassin a few months ago. But lately, as I’m sure you’ve noticed, the volume of spam has exploded. Even with SpamAssassin, the hassle of plucking the few wanted messages from my NotToMe folder, plus the growing amount of spam sent to my primary e-mail addresses (and not caught by SpamAssassin), spurred me to take the next step.
Tomorrow: Solution Ideas (continued)