techblog 

Thanks to Mark Baker who showed me this little trick.

Whenever you display and email address in a web page there is a good chance a spambot will harvest that address and add it to a database. This technique allows you to publish email addresses in a way that browsers and email programs correctly understand but very few spambots do.

The way it works is to write out the email address using HTML character data - i.e. each letter is written like &#number; . So the email address jay@nominet.org.uk gets written in HTML as follows (line breaks added for clarity)

<a href=”mailto:&#106;&#097;&#121;&#064;&#110;
&#111;&#109;&#105;&#110;&#101;&#116;
&#046;&#111;&#114;&#103;&#046;&#117;
&#107;”>&#106;&#097;&#121;&#064;&#110;
&#111;&#109;&#105;&#110;&#101;&#116;
&#046;&#111;&#114;&#103;&#046;&#117;
&#107;</a>

which ends up looking like this:

jay@nominet.org.uk

Can you tell the difference?

Some of you may be thinking that this trick will be quickly discovered by spambot authors. However I think that spambots are generally only after the quick pickings and unless this trick becomes very popular it is not going to appear on their radar.