Wednesday, November 21, 2007

How to hide your email address from spammers if you have to put it on the internet

When you put an email address on the internet, computer programs called 'spam robots' will find it by trawling over all the web pages they can find. Over the years these 'spam robots' have become more sophisticated but they can be thwarted to some degree. There are various ways to thwart them, one of which is to make your email address into an image which has no code equivalent that can be read by the programs. This is a bit nasty from an accessibility perspective - how do people with disabilities access this information?

Another way to do it is to assemble the email address with a snippet of javascript. Whilst a computer program could interpret this ('parse it'), it probably won't bother since there are plenty of other email addresses out there which are not protected at all and they may as well sell Viagra to those people.

Here is how my email address is protected. You will see how it appears at the end bottom of my website,

The code looks like this. It's a little more complicated looking than I would like because I have had to ensure that it is still valid XHTML. The comments in the code reference the sources of information I used in coming up with this.

You should note that this is NOT a foolproof way of ensuring you don't get spam but it should reduce the amount you get.

<!-- This Javascript hides an email address from spam robots -->
<!-- See The JavaScript Source!! -->
<!-- I got this to validate following advice from here -->

<!--The 'noscript' tag provides alternative contact info for people with Javascript switched off-->

<script type=\"text/javascript\">
var user = \"carl.myhill\";
var site = \"\";
document.write(\"<a href=\\\"mailto:\" + user + \"@\" + site + \"\\\" accesskey=\\\"9\\\" \\>\" + user + \"@\" + site + \"<\\/a> <em>[9]</em> \"); //]]>-->

<p><em>Contact carl.myhill at</em></p>

NOTE: This bit of code also activates accesskey 9 for your email address. This is the standard (in the UK government at least) accesskey for 'feedback' and allows users to hit Alt+9 to send you an email instead of needing to navigate to the link.

No comments: