ESP Callback Logs, under Tools → Logs → ESP Callbacks, let you verify and monitor the integration between Mumara and third-party Email Service Providers. When you send through ESPs like MumaraOne, Mandrill, SendInBlue, or SMTP2GO, those providers post webhook callbacks back to Mumara with delivery statuses, bounces, complaints, and engagement events — and this page stores every one of them.
Callbacks are organized in a tree-style file browser with one folder per ESP, created automatically once a provider starts sending data. Inside each folder, every callback is a JSON file named with the timestamp it was received (e.g. 2024-12-30 13_48_48.json). Clicking a file opens the raw JSON payload in a viewer with a copy button — handy for support tickets. Typical fields include the recipient address, delivery status (relayed, bounced, deferred, failed), the SMTP response code, and queued/logged timestamps. Callback types cover delivery confirmations, hard and soft bounces, deferrals, spam complaints, and (where the ESP supports it) opens and clicks.
Use these logs to confirm an integration works — send a test email, then look for a fresh file under that ESP's folder — or to diagnose why specific emails bounced. If no callbacks appear, check that the webhook URL is configured in your ESP account and that your firewall allows incoming requests. Keep recent files for at least 30 days for troubleshooting, and treat them as sensitive data since they contain recipient email addresses.