Author of Barebones CMS here. The message you received is associated with your IP address, which indicates that your current IP address has probably been flagged globally a known spam source. Even after you clear up the spam issue on your end, the IP information on the server side is cached for two weeks. You can always send an e-mail to email@example.com.
NodeBB is not associated with MyBB. The folks behind MyBB are not associated with Barebones CMS nor any other CubicleSoft related product.