If you’re currently using rbl.orbitrbl.com for spam blocking or filtering, you should probably remove it from your configuration immediately.
Luckily this DNSBL was not widely used, and is not part of a default MDaemon configuration, so most MDaemon administrators will not need to take any action. If you do have MDaemon configured to use it, you’re currently seeing either timeouts or errors, and shortly you will find a majority of inbound mail will be flagged as spam.
Mark Jeftovic of EasyDNS recently posted the following to the mailop mailing list.
As some of you may know, we recently took over ZoneEdit.com and it’s customer base.
We’ve found a domain on the system: rbl.orbitrbl.com which is delegated to zoneedit nameservers, broken (it is not allowed to zone transfer from it’s designated master), unresponsive (account owner is not answering email, has an address in Sri Lanka and no telephone number), is using excessive queries (~ >500M queries per day on a “free dns” domain) and attracting repeated, multiple DDoS attacks.
As such, we will be wildcarding this zone and setting a long TTL fairly soon.
If you’re actually using this RBL in your MTAs, now’s a good time to stop. (this RBL is broken on 5 out of it’s 6 delegated nameservers across 3 separate providers).
I’d like to thank Mark for giving everyone advanced warning.