preg_match()
http://www.php.net/manual/en/function.preg-match.p hp
Vše je v dokumentaci.
Test e-mailu mám takhle :
function test_email_new ( $hodnota ) {
$pattern = '/^([a-z0-9])(([-a-z0-9._])*([a-z0-9]))*\@([a-z0-9])' .
'(([a-z0-9-])*([a-z0-9]))+' . '(\.([a-z0-9])([-a-z0-9_-])?([a-z0-9])+)+$/i' ;
return preg_match ($pattern, $hodnota ) ;
}