thanks to www.webune.com for helping us with this questions.

i needed a function or class to check on my user's email to verify that the emails address they were providing was correct. so here is a useful email verification function.

this function just checks that the format of the email is correct:

function check_email($email) {
	$validation = TRUE;
	if(!eregi("^[_a-z0-9-]+(.[_a-z0-9-]+)*@[a-z0-9-]+(.[a-z0-9-]+)*(.[a-z]{2,4})$", $email)) {
		$validation = FALSE;
	}
	return $validation;
} 


hope this helps

USAGE:
if(!check_email($mail)) { 
	$error .= "EMAIL  - The Email You Provided Is not Valid";
}