Development and pilot servers

The workspace contains three additional server binaries you may notice alongside the production ones: smtp-server, imap-server, and pop-server (from the smtp_server, imap_server, and pop_server crates).

Not for deployment. These are memory-backed dev/pilot binaries used to prove out the underlying sans-io protocol session logic before sithbitd existed to host it against real storage. They have no chain pipeline, no real persistent storage, and no postage enforcement — accepted mail is logged, not delivered. For running an actual mail server, see Running a mail server and sithbitd.