I was going to run a pipermail email list on a 44 IP. While I am sure I can get it to work fine between other 44 hosts, my guess is that it will see little use if I can't make it work like any other host on the wide internet.
The latest problem again is with outside connectivity. There seems to be some sort of TTL issue going on. My network /host isn't always reachable from the internet. And it seems to depend on who you are using for internet.
My host: 44.92.21.35 Seems to work fine from a time warner cable connection in Green Bay. But other people report not being able to reach it.
Looking at other 44net hosts connected to the internet:
pinging 44.88.0.9 - Fine pinging 44.4.92.50 yes but with packet loss
So it turns out a lot of my SMTP headaches track back to this bigger problem.