Dug up the python code I used to send zephyr messages from my old Nokia 6630, tweaked it a bit to have a bit of actual UI on ASE:
what = droid.getInput("Send to %s:" % who)["result"]
droid.makeToast("Sent %d bytes" % len(zpack))
Discovered that apparently os.putenv doesn't work (or at least os.getenv in the same process didn't see the value.) Also was reminded that socket.gethostbyname(socket.gethostname()) only gets a useful local host on "real" machines, and to make things worse I was behind a NAT... so sending unauthenticated packets failed until I hardcoded the NAT's outside address as the local part of the notice unique id (an anti-harassment feature from ages ago is that unauth packets need to include their real sender IP addr; auth packets can have "privacy" and use a null value.)
Since ultimately I want to subscribe as much as I want to send, I'll need auth eventually. I could port my kerberos-v4-in-raw-perl to python today, but I've avoided that particular sin for long enough that zephyr-with-kerberos-v5 is almost viable... on top of that, since I actually need NAT support in practice, I should start thinking about a zephyr-v5 relay. (That should be of more general use - otherwise I should instead just do an xmpp/zephyr relay and use existing xmpp clients on the phone, right?)