The Perl regex is also incorrect, since it assumes that comments were stripped beforehand. It also requires you to have backend processing that knows that <a . (kidding) b @ example.com>, <"a.b"@example.com>, and <[email protected]> all refer to the same email address. It would help if people knew that you need to look at RFC 821(/2821/5321) to figure out what constitutes a valid email address instead of RFC 822.