JavaScript Regex to check email format like Facebook registration form

Question

I currently use this pattern for checking email format:

/^(("[\w-+\s]+")|([\w-+]+(?:\.[\w-+]+)*)|("[\w-+\s]+")([\w-+]+(?:\.[\w-+]+)*))(@((?:[\w-+]+\.)*\w[\w-+]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$)|(@\[?((25[0-5]\.|2[0-4][0-9]\.|1[0-9]{2}\.|[0-9]{1,2}\.))((25[0-5]|2[0-4][0-9]|1[0-9]{2}|[0-9]{1,2})\.){2}(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[0-9]{1,2})\]?$)/i

But it is not the same format with Facebook's pattern.

For example: email@abc.co.jp.jp is incorrect but it's valid to the pattern above. I need a pattern follow facebook format.

Answer 1

Facebook signup page has a script that defines function is_email as:

function is_email(a){return /^([\w!.%+\-])+@([\w\-])+(?:\.[\w\-]+)+$/.test(a);}

Not quite RFC822: http://www.ex-parrot.com/pdw/Mail-RFC822-Address.html