I use this
@\"^([\\w\\.\\-]+)@([\\w\\-]+)((\\.(\\w){2,3})+)$\"
regexp to validate the email
([\\w\\.\\-]+) - this is f
([\\w\\.\\-]+)
Try this on for size:
public static bool IsValidEmailAddress(this string s) { var regex = new Regex(@"[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?"); return regex.IsMatch(s); }