Email Spam – The Growing Threat

spam filtersSpam, the dark side of email convenience. Wikipedia says…

E-mail spam, known as unsolicited bulk Email (UBE), junk mail, or unsolicited commercial email (UCE), is the practice of sending unwanted e-mail messages, frequently with commercial content, in large quantities to an indiscriminate set of recipients.

By some conservative estimates, spam comprise of more than 90% of all the emails sent worldwide today.

E-mail spam today is sent via “zombie networks”, networks of virus- or worm-infected personal computers in homes and offices around the globe; many modern worms install a backdoor which allows the spammer access to the computer and use it for malicious purposes. This complicates attempts to control the spread of spam, as in many cases the spam doesn’t even originate from the spammer.

The California legislature found that spam cost United States organizations alone more than $13 billion in 2007, including lost productivity and the additional equipment, software, and manpower needed to combat the problem.

Spam Filters – The Saviours

The menace of spam has resulted in the development of many anti spam software. No wonder that most of the security software vendors have developed products, which try to  block spam. All of them claim to be the best in the industry, and it is very difficult for an individual to compare different spam filter software before making a decision.

However, Virus Bulletin, an independent analyst has started testing the major anti-spam software for their effectiveness on a monthly basis. For the last two months, they have been running a certification scheme for anti-spam products which will fulfil the huge demand of the industry for a comparison to choose, which is the best anti-spam software..

The tests use Virus Bulletin’s live email stream, which is sent to all the filters participating in the test in random order, thus exposing each to exactly the same email stream, in real time. The tests measure both the false positive rate and the spam catch rate of the products, and Platinum, Gold and Silver certifications are awarded based on products exceeding predefined benchmarks in both measurements.

They fix a deadline and ask all spam filter developers, who want to get their spam filters benchmarked, to submit their products by this date. After this, they install the submitted products and bombard them with a corpus of emails.

The email corpus consists of all email sent to the domain as well as a spam corpus provided by Project Honey Pot and randomly assigned to existing addresses. All emails are forwarded in real time. The products receive approximately one email every four seconds, or 20,000 emails a day.

Ok, That’s Enough. But Which is the Best Anti Spam Software

And the results of this month’s testing are out. This is shown in the following chart. On the Y-Axis, you have the SCRate (Spam Control Rate), which imply the effectiveness with which the spam blocking software was able to identify a spam. The Y Axis represents FP Rate (False Positive Rate), which imply the error rate, by which the spam filter tagged a non-spam mail as spam.

See the results yourself.

best spam filter comparision

The details of the results can be seen on the Virus Bulletin website.