Anti Spam Software

Buyer's guide - what to look for in Anti Spam software

Spam has become a fact of every-day life and is something that we can all recognise. Officially it can be described as unsolicited bulk messages, be they in the form of email, instant message, web forum posts or any other method of information delivery. The focus of the majority of consumer Anti Spam software products is of course email spam.

Spam emails account for up to 85% of all email traffic. Its proliferation is due to the extremely low cost for a spammer to operate, needing only a tiny response rate to make the activity commercially viable. Luckily, Anti-Spam technology has reached a stage where we should no longer have to deal with spam email at all.

Spam protection comes in two flavours - server (or mailbox) level protection, and email client protection. Server level protection is implemented by your email provider to filter messages before they hit your inbox. All the major webmail providers use anti-spam technology (such as Gmail, Yahoo!, MSN) as do major ISPs. If however you have an unprotected mailbox and connect via an email client program to download your email, you will quickly find yourself hundreds, if not thousands, of unwanted messages clogging up your inbox - a situation made worse if you have posted your address online.

Even if your email does benefit from server side protection, it may not be affording you the protection you need. If you use an email client (such as Outlook, Outlook Express, Mail, Windows Live Mail, Entourage or Thunderbird) and regularly see unwanted email then these software titles are for you.

Most good anti-spam software products will plug in to your email client and provide continuous protection in the background - filtering messages as they are downloading and separating suspect email into a designated folder. Check the software to ensure that your email client is protected.

Spam messages are detected using several rules. The most common are:

• Bayesian filters - which calculate the probability of a message being spam by looking at the occurrence of words and phrases that make up the email, and modifying these occurrence rules according to the emails you have accepted and rejected in the past. Bayesian filters are also updated by the software vendors on the basis of feedback from their users.


• White lists - a list of email addresses that you will always let through the spam filter because you trust the sender


• Black lists - a list of email addresses that you have marked as spam senders

Most anti-span software will allow you to fine tune detection rules to suit your needs. For example, you can set the Bayesian filters to be more aggressive at targeting suspect emails, or you can set the software to delete all spam messages instead of moving them to a spam folder.

More advanced features to look our for include:

• Phishing protection - the detection of links within emails that may not be genuine


• Challenge emails - return an email to the sender and ask them to manually type a code before the email is delivered

If you are keen to never see spam email again, a combination of a server level and client level solution will afford you maximum protection.