Netmail

Netmail uses the same FTN packet message primitives as echomail, with routing metadata carried in control lines such as INTL, FMPT, TOPT, MSGID, REPLY, FLAGS, and Via.

The runtime can parse and compose those control lines, preserve raw packet message bodies, make local/direct/hub/crash/hold/unknown routing decisions, deliver local netmail, queue forwarded netmail, queue AreaFix replies, and materialize pending outbound netmail through net scan.

Netmail duplicate keys follow ADR 0023: MSGID is hashed with SHA-256 across the network, origin address, destination address, and MSGID. MSGID-less messages use the shared fallback hash policy with timestamp-bucket clock-skew candidates.

See Netmail Routing for the current routing decision scope and runtime boundaries.