Every message finds the shortest reliable path.
A high-availability relay node built for one job: accept authenticated mail, keep it encrypted in flight, and hand it to the next hop without drama, delay, or drift.
A relay, not a mailbox.
The node holds nothing longer than it must. Mail arrives authenticated, moves through in memory where possible, and leaves. Everything below is table stakes — enforced, not optional.
Enforced TLS
Opportunistic where required, mandatory where policy allows. Plaintext delivery is refused for domains that advertise MTA-STS.
Authenticated ingress
Every sender presents credentials. Unauthenticated submission is dropped at the door — no open relay, ever.
Sub-50ms handoff
Median accept-to-next-hop under a coffee sip. Connection reuse and warm route tables keep the pipe hot.
Signed & aligned
DKIM signing on egress, SPF and DMARC evaluated on ingress. Alignment failures are logged, quarantined, and reported.
Dual-stack routing
Native IPv6 and IPv4 next-hop selection with automatic fallback and reputation-aware source addressing.
Backpressure aware
Graceful deferral over silent loss. When a downstream is slow, mail queues with honest 4xx codes and retries with jitter.
Four hops from door to done.
A message crosses the node as an ordered sequence. Each stage is a gate: pass it clean, or don't pass at all.
Ingress & auth
The connection opens over TLS, the sender authenticates, and the envelope is checked against policy before a single byte of body is accepted. Fail here and you get a clean 530.
Inspect & sign
Headers are validated, SPF and DMARC are evaluated, and an outbound DKIM signature is applied. The message is now provably from where it says it's from.
Route selection
The node resolves the recipient's MX, ranks candidate next-hops by reachability and reputation, and picks the shortest path that will actually accept the mail — IPv6 first.
Handoff & receipt
Delivery is attempted, the downstream's response is recorded, and the message leaves node memory. Transient failures re-queue with exponential backoff; nothing is silently dropped.
Boring on purpose. Correct by default.
Email infrastructure earns trust by being predictable. The node runs current standards, publishes its posture, and does nothing clever with your mail.