Phase 5 code is complete, committed (b2692e4) and verified on the server.
Everything at SelfPost's boundary is proven (auth, sender binding, no open
relay, valid DKIM signing, delivery to the recipient MX over TLS). The one
open item — the receiver accepting the message into its inbox — is gated by
mc.mixfed.ru's DNS cache / own-domain policy, not a relay defect; a background
loop retries until it lands.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
mix
ec4d4b9faa