Set sender identity, test SMTP, understand the queue and fix delivery failures.

Configure transport

1. Open email settings and choose SMTP for predictable authenticated delivery.
2. Enter the exact host, port, encryption mode, username and password from the mail provider.
3. Use a From address authorized for the sending domain.
4. Save, then use the built-in test message.

DNS and reputation

Publish SPF and DKIM records provided by the mail service. Add DMARC after verifying all legitimate senders. DNS authentication does not fix invalid SMTP credentials, and successful SMTP acceptance does not guarantee inbox placement.

Use the mail queue

Queued messages retain delivery state and a sanitized failure reason. Fix the transport problem before retrying the batch. Repeatedly clicking retry without correcting credentials, TLS, rate limits or recipient rejection only adds noise.

SymptomCheckAuthentication failedUsername, password, provider app-password requirements and source-IP restrictions.TLS errorHostname matches certificate, system CA bundle and correct encryption/port combination.Accepted but not receivedSpam folder, provider event log, SPF/DKIM/DMARC and recipient suppression list.