quindi cosi dovrebbe andare bene?


return preg_match('/^(?:[\w\!\#\$\%\&\'\*\+\-\/\=\?\^\`\{\|\}\~]+\.)*[\w\!\#\$\%\&'\*\+\-\/\=\?\^\`\{\|\}\~]+@(???:[a-zA-Z0-9_](?:[a-zA-Z0-9_\-](?!\.)){0,61}[a-zA-Z0-9_-]?\.)+[a-zA-Z0-9_](?:[a-zA-Z0-9_\-](?!$)){0,61}[a-zA-Z0-9_]?)|(?:\[(??:[01]?\d{1,2}|2[0-4]\d|25[0-5])\.){3}(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\]))$/', $address);