Debug Failed Deliveries End-to-End

Fast triage

1. Is the integration active?
2. Is the routing active and mapped to the right inbox?
3. Is destination endpoint reachable and returning expected status?

Failure patterns

4xx responses

Usually payload validation or authentication mismatch.

5xx responses

Destination instability or upstream incident.

Timeout/connection errors

Network/DNS/TLS or provider availability issues.

Root-cause workflow

Step 1: Scope

Determine if failures are isolated to one integration or systemic.

Step 2: Evidence

Extract delivery attempt diagnostics from activity.

Step 3: Fix

Apply targeted fix (credentials, URL, provider settings, rules).

Step 4: Revalidate

Use integration tests, then replay selected messages.

Escalation criteria

Escalate when failures persist after credential + endpoint validation, or when retry queue growth threatens SLOs.