Is there a PHP library for email address validation? [closed]

I need to validate the email address of my users. Unfortunately, making a validator that conforms to standards is hard.

Here is an example of a regex expression that tries to conform to the standard.

Is there a PHP library (preferably, open-source) that validates an email address?

Answer

I found a library in google code: http://code.google.com/p/php-email-address-validation/

Are there any others?