Email Channel Plugin

The Email channel plugin is an alert_deliver plugin that sends Core-rendered alert messages through SMTP. Core owns alert meaning, rule evaluation, and recipient selection; this plugin owns SMTP transport validation and delivery.

Highlights

• Supports STARTTLS, TLS, and plain SMTP connection modes.
• Sends Core-rendered subject and body text selected by language.
• Respects recipient profile language and connector fallback language.
• Bounds timeout, retry count, and backoff, retrying only transient SMTP failures.

Before Registration

• Prepare SMTP host, port, sender address, security mode, username, and password.
• Configure a test recipient when you want connection tests to include a labeled test message.
• Confirm sender, relay, TLS, and authentication policy with the mail server first.

Operations Tips

• Password and SMTP auth material must not appear in logs or action responses.
• Stable Message-ID and diagnostic headers can help downstream mail tracing.
• Recipient routing is determined by Core alert routes and delivery payloads, not by connector-local recipient lists.

Operator Views

• Channel settings manage SMTP endpoint, security mode, sender, authentication, timeout, and retry policy at the transport level.
• Email has no standalone channel page. Draft diagnostics appear in the registration/edit form and test-result details.
• The form assistant previews the rendered subject/body, recipient parsing, TLS/auth summary, and retry schedule without sending mail.
• Connection tests distinguish configuration validation from actual test-message delivery, helping operators isolate mail-server policy issues.
• Delivery results link back to Core delivery sessions and show success/failure, retryability, and downstream SMTP responses.

Delivery Model And Limits

• The plugin sends a Core-rendered title and body through an SMTP envelope.
• If recipient profile language is available, the plugin selects that rendered language; otherwise it uses the channel fallback language.
• Only transient SMTP errors are retried within bounds; authentication failures and invalid recipients should fail fast for operator correction.
• Attachments, bulk email campaigns, and mailing-list management are outside alert-channel scope.

Example Workflows

• If alert email does not arrive, check Core delivery session, SMTP auth, relay policy, TLS mode, and recipient server rejection reason in order.
• If the form preview is correct but delivery fails, run the explicit connection test first, then add test_recipient and run the delivery test.
• If multilingual messages look wrong, review recipient language, notification language, and fallback language.
• For suspected duplicate email, compare Message-ID, delivery session id, retry count, and downstream mail-gateway traces.