SMTP roles

Mail servers exchange messages using SMTP. Mail users and applications should normally use an authenticated submission service rather than unauthenticated relay.

Authenticated submission

• Use the assigned JKMail hostname.
• Use TLS.
• Authenticate with the complete mailbox identity where required.
• Do not share mailbox passwords between unrelated applications.

Application mail

Applications should use a controlled SMTP identity or approved relay workflow. Successful application-level submission does not by itself prove that final mailbox delivery succeeded.

Delivery confirmation

For troubleshooting, trace the message through submission, queue processing, receiving-server response and final mailbox delivery.