Verdict READY. Real Vaultwarden test email travelled app → on-box go-smtp
shim → relay-leg → Resend → real inbox, From felhom.eu, TLS/DKIM-aligned,
Resend key never on the demo guest. Q4 central finding: raw-MIME passthrough
via Resend SMTP delivers faithfully; parse-then-API silently drops inline
(CID) images — hub leg should be SMTP passthrough, not the structured-API path.
Probe code throwaway (not committed); cleaned up from guest 9201 + host 180.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NB4fVgvEurdKgyG8KoQSzC
