Understand the sample
Open Reach → Deliverability → Inbox & Reputation → Seed inbox testing. Monitoring inboxes are authorized mailboxes Reach can read for sample placement checks.
A sampled inbox result is not a guarantee for the entire audience. Delivery acceptance, inbox placement and recipient engagement answer different questions.
Prepare the accounts
- Connect the intended sending account and at least one supported readable monitoring inbox.
- Confirm that your organization authorizes reading those inboxes and receiving test messages.
- Check connection readiness and the candidate account selectors. If no eligible account appears, review sender connection and inbox-reading support.
Monitoring accounts and historical timestamps are hidden. Run sends a probe; Check updates the observed result.
Account details and configuration values are hidden.Add a monitoring inbox
- Choose an eligible account under Monitoring inboxes.
- Review the exact mailbox before choosing Add.
- Verify that it appears in the monitoring list. Multiple inboxes can provide a more useful sample when your organization has authorized them.
Run an intentional probe
- Choose the intended sender under Probe delivery.
- Confirm the monitoring audience before choosing Run. This sends test messages; it is not a preview-only action.
- Wait for delivery, then use Check for the relevant probe to update observations.
- Inspect the resulting placement rather than assuming an accepted send reached the inbox.
Interpret results carefully
Use the observed inbox or other placement state as evidence for that probe and monitored mailbox. A pending or absent observation may mean the message has not been found yet or that reading is unavailable.
Consider the size and coverage of the sample, the age of the check, and the sender used. Do not quote a sampled rate as guaranteed inbox delivery for customers or a production audience.
Maintain monitoring
Recheck accounts when connection authorization changes. Disable a monitoring inbox only when it should no longer be used for testing, after reviewing the effect on your sample.
Keep monitoring-account identities and probe records private. Share a redacted view if you need help investigating a result.
Troubleshooting
- No candidate inbox: check supported reading access and sender permissions.
- Probe fails: inspect sender readiness and the reported mail error before retrying.
- No observation: wait for delivery and check the intended probe; verify that the monitoring account is readable.
- Mixed placement: inspect sender setup, message content and sample coverage, then review broader Deliverability evidence.
Related guides
Ask your workspace administrator for access or contact support with the page name and a sanitized error message.