Due to a high volume of spam accounts being created for the purpose of advertising we have found it necessary to disallow certain email addresses. Hopefully you haven't seen any of the spam posts, since we've got some quick moderators that do an amazing job of taking them down
If you are being told that your email address has been banned when attempting to register an account, you will need to use a different email address. Try to avoid using any of the more common, free email providers.
Do not attempt to register more than 5 times per day or you may be banned.
On behalf of the rest of the rpc1.org crew, I apologize for the inconvenience and hope for your understanding.