We have received reports that the RBL (Real Time Blacklists) JAMM DNSBL has gone down. We have removed it from our database and no more alerts should be received.
The JAMM DNSBL was a public data base which listed suspected sources of spam which has recently closed its doors. Most RBLS (Real Time Blacklists) when they wish to dissolve will commonly blacklist the entire internet in order to get the attention of those people using them to stop attempting to contact their IPs.
We apologize for any inconvenience this may have caused, please let us know if you have any other questions or concerns.
http://www.jammconsulting.com/policies/dnsbl.shtml
MxToolBox is not affiliated with any Blacklists, we just provide a public tool that can be utilized to see if you are on a Blacklist. If you are on a Blacklist, rest assured as we do offer Blacklist Protection! For more information please feel free to visit our website or email us at info@mxtoolbox.com.
We’re always looking for new Blacklists to add, so if you want to suggest one to us, please send an email to support@mxtoolbox.com.
For information about other Blacklists that have shut down or Blacklists that are having problems, view this forum post.