I had a corrupted RPM database, and rpm told me to contact rpm-list. This list is closed, and only members can post to it. This is not very user friendly, and the address to report such bugs should be changed or removed.
The list is open, but you need to subscribe by sending mail to rpm-list-request. Meanwhile, try "rpm --rebuilddb".
I realize you can subscribe to the list and get your message through, but I think that it is quite user-unfriendly to tell people to send email to a particular email address only to have that email bounce back with a "you must subscribe to this list" message. Besides, if the solution to the problem reported is as simple as running rebuilddb, why does not RPM just do that for you, or tell you to run that command yourself? That would be the most user-friendly solution. But if you want to build a system that is only usable by savvy users, then leave it as is; I was just pointing out that this way is not very user-friendly.