[bitmedley]

Encoding your email address to hexadecimal may prevent some less sophisticated crawlers from capturing your email address.

mailto: -> mailto:

[e-mail] -> abc@gmail.com

Then instead of:

<a href="mailto:[e-mail]">[e-mail]</a>

Use this:

<a href="mailto:&#097;&#098;&#099;&#064;&#103;&#109;&#097;&#105;&#108;&#046;&#099;&#111;&#109;"> &#097;&#098;&#099;&#064;&#103;&#109;&#097;&#105;&#108;&#046;&#099;&#111;&#109;</a>

Or this ("mailto:" also encoded):

<a href="&#109;&#097;&#105;&#108;&#116;&#111;:&#097;&#098;&#099;&#064;&#103;&#109;&#097;&#105;&#108;&#046;&#099;&#111;&#109;"> &#097;&#098;&#099;&#064;&#103;&#109;&#097;&#105;&#108;&#046;&#099;&#111;&#109;</a>

source: http://www.wbwip.com/wbw/emailencoder.html

[sebazzz]

Wouldn't any decent HTML library, probably already used by the crawler, convert that back to plain text?

[onion2k]

If you're crawling the web looking for email addresses you're probably not bothering to parse the HTML. You don't need to: you can just grab the email from the raw response from the web server, along with any new links to follow.