Observe
Troubleshoot a send
Start with the message, then follow the evidence.
Preview guide. Confirm API behavior and connection details against the live service before production use.
Start with the message ID
Find the request and its message reference. Note the sender, recipient, request time, and response, while keeping private message content and credentials out of public support channels.
Authentication or domain errors
Check that the API key is present, the correct environment is configured, and the sending address belongs to an authenticated domain. Read the returned error before retrying.
An address that bounced
Inspect the bounce reason and receiving server’s response. An unknown-user response typically calls for correcting the address rather than repeatedly sending to it.
A message that is delayed
Check the latest delivery event and whether the service is still retrying. Avoid immediately resending the same message while its final result is pending.
Keep buildingSend your first email