Hi,@Roger Roger
Thanks for posting your question in the Microsoft Q&A forum.
According to your description, you set up a redirection rule and the original recipient did not receive the email. This is the expected behaviour, redirection is different from forwarding. When you use redirection, the email is not delivered to the original recipient and no notification is sent to the sender or the original recipient.
You can refer to this link for details:https://learn.microsoft.com/en-us/exchange/security-and-compliance/mail-flow-rules/mail-flow-rule-actions#actions-for-mail-flow-rules-in-exchange-online
If my answer is helpful to you, please mark it as the answer so that other users can refer to it. Thank you for your support and understanding.