Inbox/outbox stuff has been replaced by this:
Just run Sync-Starmap (SyncStarmap.exe), and it'll check for inboxes and get them if there are any, and it'll merge them automatically. Then it'll check to see if you've made entries that it should outbox, and if so it makes an outbox and tells you where to send them. You do that, of course. :P

Sync-Starmap will outbox entries in every outbox until it gets an inbox which contains the entries. Then it stops sending them unless you've changed them, etc. If you modify an entry, it will start sending it in outboxes, etc.

On the server end, there's a CreateInbox3 program which is run to merge outboxes and make inboxes. Then the inboxes have to be uploaded to the site, etc. The source to this is actually in syncsm.cpp, since it shares so much code with Sync-Starmap. Anyone can do this, but the site URL to get inboxes from is hardcoded into Sync-starmap right now.