Methods of Spam Filtering

Spam is an annoyance that has been around as long as the Internet itself. Every one of us who has an active email account and who is a frequent user of the Internet has more than likely experienced the growing problem of spam at some point.

Whether you use your email account for business or for pleasure it does not matter to the spammer, all the matters to them is getting their message across to you. Once we have fallen victim to our first spam email the process never sees to stop; we just seem to start getting more and more and we are left wondering how the spammers got our email account address in the first place. Spammers 'harvest' our email addresses off the Internet. If you have ever posted your email address anywhere on the Internet such as a forum then chances are you are being signed to a spammers mailing list as we speak.

Many people class spam as unsolicited and commercial when it really should bely classes as automated. As that is the way spammers send their mail; it is automated. However it should be noted that if you are signed up to newsletters or if you have purchased anything from the Internet you will still be sent emails about these things even though these are also classed as being automated.

The most common content of spam messages are products being advertised, which makes up 25% of spam messages, financial messages, which is 20% of spam messages, adult content, 19% of spam sent and health / pharmaceuticals being 7% of the spam that we receive. All of these aspects make up the 90 billion spam messages that are sent everyday, which makes up 80-85% of all of our incoming emails.

The one thing that spammers have to do is to deliver their message. Although spammers seem to get around all other forms of barriers that are created through the use of spam filters, so if we can create filters that can stop spam primarily on the message there would be no way of getting around it. This would work, for example, if you set the filter to look for the word click. Just by doing this and setting your filter to stop one word you would catch 79.7% of spam emails. So what would happen if spammers sent their messages containing purely images? Well some spammers already do this and sometimes get done but if you want to ensure that you catch all of them you can set your filter to scan for HTML as well as the text of your message. This will work due to the fact the email message will more than likely contain a URL to a spam site as well as containing text with the image name that will be deemed as spam by your filter.

One thing that is worse than receiving spam emails is even getting false positives blocked by your filter. False positives are genuine emails that we wish to receive that get cached up in our email filters. When the filters that we are using becomes extremely good at what they are designed to do we start to not notice what these filters are catching, meaning that we could be losing genuine mail. To stop this from happening it is important that you keep a check on what your spam filter is doing.

Source by Helen Cox