Where in this Clean Email preg_match is it saying no empty value?

Code PHP:
// Clean Email
if (!preg_match("/^[A-Z0-9._%-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/i",$email)) {
    header( "Location: $errorurl" );
    exit ;
}

I already use this statement to clean empty values so I would like to remove it from the above statement. Do you know how?

Code PHP:
// Clean All
if (empty($name) || empty($email) ||empty($comments)) {
	header( "Location: $errorurl" );
	exit ;
}