// define a regular expression for "strange looking" but syntactically valid addresses
$validButRare = "^[a-z0-9,!#$%&'*+/=?^_`{|}~-]+(.[a-z0-9,!#$%&'*+/=?^_`{|}~-]+)*@[a-z0-9-]+(.[a-z0-9-]+)*.([a-z]{2,})$";