We've all seen it before, junk mail being delivered to our email inboxes. It seems to be a continual cat and mouse game between the spammers and the anti-spammers to filter out all the garbage automatically.

Sometimes the antispam software works well, but next week the spammers come up with a new way to get around the filters. It's big business, at your expense.

According to recent studies and our own tests, junk mail comprises over 95% of the emails flowing on the internet. Intelligent mail systems block the majority of these so that only about 10% actually get delivered. Of that 10% of junk email about 90% will get filtered out, leaving a small portion left to go to your inbox for you to sort through.

What you can do

So what can we do about all this junk mail? Apart from software filters that you probably already have in place at your ISP, there are a few important rules for everyone to follow that will ensure they don't get any junk mail, and they're easy to follow.

1. Don't let them get your address

The most effective way to not get any junk mail is for the spammers to not know your email address. They use a number of methods to get your email address into their database.

2. Fraudulent / compromised sites

Some sites also sell the information they gather, so check the privacy statement on sites before giving away too much information. Consider if you would give the details to a person who walked up to you on the street, and act accordingly. Sites can be compromised for security and applications installed on them that can pose as a legitimate site and store your details for their own purposes. The latest versions of Internet Explorer and Firefox have checks in place to notify you if a site has been listed as being compromised, so consider upgrading or installing the up-to-date versions.

3. Website scans

If your email address appears on a website then it is very likely you are on a spammer's database. Even if the address is hidden on the site, the spammer's robots can detect and store email addresses. We did a test and placed a hidden email address in the footer of a moderately busy website. Less than a day later we started receiving junk email from a number of sources. Keep your address off websites if possible. For contact details, use a web form instead that doesn't list the email address in its source. Out of interest, try doing a Google search for your email address, you might be surprised at the results. If your address is listed on a site you don't have access to change yourself, consider contacting the site and asking them to remove your details.

4. Dictionary

If your email address uses a common name, then it is easy to guess. Domain names are public knowledge, so the spammers only have to guess the part before the @. Consider using an address that includes your first and surname or a mix of initials. Just make sure that it's not too hard to spell out to someone over the phone!

5. Use disposable addresses

There are many free web-based email providers available: Hotmail, Yahoo, GMail to name a few. If you are required to use your email address to access a website, consider signing up to a free webmail for all the sites you don't want your details. Then after a while you can close the account and the spammers still don't have your real address. If you have the ability to create aliases to your email account on your mail domain, you can use these to forward emails to your main account, and use those names when signing up to online resources. Then if too much junk mail starts coming to an alias, just shut it down.

6. Don't get angry

Spammers use the shotgun approach to marketing. They don't care if the email they send gets to you personally, they just have a target percentage of successful deliveries to get. If you get junk email, tell your computer to learn it and then delete it. Don't bother replying to the sender, they probably use your reply as a positive sign that you received the email and read it, and wouldn't even bother to read the contents of your response.