You wrote John doe <Johndoe@gnail.com> did you mean <johndoe@gmail.com>
This giant contacts list, shows public listings that spammers have, and your own listings can be uploaded (staying private without going public). You can publish your email address as public or private.
You can prove that an email is yours and you can remove yourself from the list. It could help you find correct domains.
The other half of baking is how to keep it away from spammers. (Perhaps its a service only available to established users. And if people complain the spammers could be tracked down.)-- pashute, Jul 07 2011random, halfbakery