Enter an email address to test; the results will be accrued below. See if you can break it!
You may edit the test regular expression; the CATS regex is shown for your reference. Your edits will be immediately available for testing.
If you find a regex you like, please cut and paste it and the results into an email and send 'em to Jon Plummer. The idea here is to find a minimal regex that passes obviously valid email addresses, fails obviously invalid email addresses, and does not pass addresses that CATS wouldn't like.