Studies have shown that email addresses encoded into html hex entities are virtually ignored by harvesting robots. If you absolutely must put an email address into a web page, this will make it look perfectly normal to your users, but will cut down significantly on the number of harvesters finding it. The method I'm providing here encodes the email address in such a way that users will see it as if it is a normal mailto, and also provides a flag for obfuscating the address as well. Obfuscation provides an extra level of anti-spam security, but will require that your users are smart enough to know how to fix the obfuscation.
If you're a developer, you can download the php source code for encoded_mailto(). Otherwise, I've provided an interactive form below that will generate HTML code for you to copy and paste into your website.
Type in the email address that you would like to encode: