I e-mailed Burger (the previous owner of logicware.com) about it and here is his reply.

As you may know, Logicware died over three years ago. The list server was
moved to "jazz.contrabandent.com" and is still running. I've asked Inatel to
direct jazz.logicware.com to my list server's static IP address and I think
they'll honor my request.

Anyways, update your copies of Jazz 2 to pointer to jazz.contrabandent.com
instead of jazz.logicware.com.

Bill Heineman

Well, this is good news. =) It should be a long time before we have troubles with this again. Everyone should update their registries (or jazz2.exe) to jazz.contrabandent.com as Burger said. Although jazz.logicware.com should still work as long as it redirects to jazz.contrabandent.com, as they seem to be doing, jazz.contrabandent.com will be more reliable as there will be only one point of failure, not two.

The registry key, if anyone does not remember, is HKEY_LOCAL_MACHINE\SOFTWARE\Epic MegaGames\Jazz Jackrabbit 2\1.23\List Servers. Perhaps someone could make a patched jazz2 executable, too?

Yay! Hurrah for working list servers! *Dances and rejoices*

Slightly off-topic, but has anyone visited Burger's homepage?
He likes Bloom County and writes fan fiction and stuff in addition to coding a lot of cool games...Wow, Burger is a cool guy! =)