Configuring a device
Updated on 2026-08-13
Point the device at the relay's LAN address and one of these ports:
| Port | Transport | Default |
|---|---|---|
| 587 | STARTTLS | enabled - use this |
| 465 | implicit TLS | enabled - for devices that only do SMTPS |
| 25 | no encryption | disabled - opt in only on a trusted LAN |
Use the local username and password from add-account as the SMTP credentials. AUTH LOGIN
and AUTH PLAIN are both offered; most older devices need LOGIN.
The relay generates a self-signed certificate on first start covering its hostname, its LAN addresses and loopback. Devices that verify certificates need it imported, or you can supply your own.
Whatever sender address the device is configured with is ignored. The account's address is used instead. That is deliberate: it means a misconfigured or compromised device cannot send as anyone else in the customer's domain.