Site owners typically post an email address to facilitate contact with readers. The problem is that this might get harvested by specialized crawlers and sold to marketing companies, resulting in a ton of spam. Webmasters have devised several ways of obfuscating the address to make it harder for spammers to grab them. Some of the techniques include:
1. Creating an image — Instead of giving the email address in text, it may be typed out in Photoshop and saved as JPEG or GIF. The image is then embedded on the contact page. It’s easy to read for humans but tough for web crawlers.
2. Spelling it out — This usually involves a creative way of writing, often involving spaces and special characters. For example, the email address may be spelled as “[(name)] AT [{domain}] DOT [/com/]”.
3. Using Javascript — Coding magic can be used to separately generate each part of the address. This way, it will only be visible once the code is executed in a browser. Crawlers will not see the address at all.
A word of caution: Google has reached a level of sophistication that allows it to execute Javascript code and read any text generated. As a result, some “hidden” email addresses may be included in search result snippets. Matt Cutts recommends dropping the third technique in favor of others.
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JavaScript and email addresses –