A very common habit for most Internet users while posting their email address in public forums, new groups and discussion is to obfuscate their email using various techniques to prevent spammers and email harvesting bots from getting their email id.
Problem with Current Email Obfuscation
Some of the more common examples used quite frequently have been listed below
emailme[at]domain.com emailme [at] domain [ . ] com emailme(at)domain(dot)com
Posting email addresses with obfuscation like in the above example is counter productive and non-intuitive. Not only are users are expected to copy the email address and manually edit it but an assumption is made that the user who sees the Obfuscated email knows where to edit it the Obfuscated email.
Another very common method to solve this problem has been to use images which display the email addresses. This again is counter productive and non-intuitive as it requires the user to manually read out and type the email addresses.
Semantic Anti Spam Email Obfuscation Solution
A simple solution is to use HTML Character Entity  to Obfuscate the email address.
For example for the email address
firstname.lastname@example.org we could encode each letter with their respective HTML Character Entity to give us the following HTML code given below.
The code above will render as
email@example.com when viewed as a HTML page in any browser.
Semantic Email Obfuscation For Better User Experience and Usability
Using Semantic Email Obfuscation not only helps acts as an anti-spam protection measure against spammers. But is also helpful from a User Experience and usability point of view. You can easily use it in anchor tag with
href="mailto:". See the example below. A user can easily copy or click on the link to get your email address.
<a rel="nofollow" title="My Email Address" HREF="mailto:firstname.lastname@example.org"> Email Address </a>