All new registrants get banned email message

[dantoniuk]

I'm having a problem where new users fill out the Registration page, then get the following message:

"The administrator has banned your email address. You will need to change your email address in order to continue. If you think this is done in error, please click here to contact the administrator."

But when I go into the CP and select "View Banned Users", it is empty.

I tested this myself, trying to create a new user, and also received the message. Any ideas on what is going on?

David