A bounce is an automated delivery report. It usually explains why a message was rejected or could not be delivered.
- Address not found: check the complete recipient address for typos.
- Mailbox full: the recipient may need to free space.
- Message too large: reduce the total message size or use an appropriate file-sharing link. The recipient may have a lower limit.
- Blocked or rejected: the receiving service may have a security or policy restriction. Keep the diagnostic code.
- Delayed: the server may still be retrying. A delay notice is different from a final failure.
Correct the stated problem before resending. Repeatedly resending an unchanged message may not help. See sending troubleshooting and message-size guidance.
If you need help, open a support ticket with the diagnostic error and code. Remove quoted original message contents, attachments, passwords, and patient information.
