OK, maybe title should actually be “Prevent email address harvesting with jQuery”. But anyway – I came up with a technique for our company web site today which will hopefully prevent some of the email addresses that we publish being picked up by email address-harvesting bots. The idea is that an email address is put on the website using the following obfuscation:
<span class='email'>joebloggs [at] example [dot] com</span>
And then transformed by JavaScript into:
<a href='mailto:joebloggs@example.com'>joebloggs@example.com</a>
It’s a progressive enhancement in that the content is still quite legible by people with JavaScript turned off. Here’s the jQuery script that does it:
$(function() {
$('.email').each(function() {
var $email = $(this);
var address = $email.text()
.replace(/s*[at]s*/, '@')
.replace(/s*[dot]s*/g, '.');
$email.html('<a href="mailto:' + address + '">'
+ address +'</a>');
});
});
I’m perhaps being naïve about how email addresses are collected these days, and maybe embedding email addresses in images is a better approach – but this was quick and simple and worth a try.
Duncan Smart's Blog 
I was reading a little bit lately, and I recall seeing somewhere that putting your e-mail into the page as “foo [at] bar [dot] com” doesn’t really protect you at all – Google(and I assume other search engines as well) strips out the special characters, and means that all you need to search for is “at bar dot com” to find valid e-mail addresses that users have attempted to secure using this method.
As a quick test, try searching “at gmail dot com” – you’ll see that on the first page alone, there are a few e-mail addresses. If you try searching using “[at] gmail [dot] com”, you’ll notice that you get the exact same results – because Google strips out the special characters.
Just my two cents.
It’s a nice concept and I think it can be improved. I don’t usually let emails on page, but every time that I need to do it I’m using PHPThumb to convert the email string into a image.
mcloide.wordpress.com
Thank you. It was just what I was looking for!