Problem: email should allow +/- characters in user, - in domain.
dash (-) should be allowed anywhere in an email address or domain.
plus (+) is allowed in the username (many people use this for categorization, especially at gmail)
Solution :
>var regex = new RegExp("^+(\.+)*@+(\.+)*\.({2,})$","i");
This will validated also emails like: username1+username2@gmail-domain.co.uk