In this post, let’s have a look at the error message “5.7.504 – [email@contoso.com]: Recipient address rejected: Access denied” that you get when working with Microsoft 365 Exchange Online.
These are the errors that you usually receive when there is a problem in delivering the email message that was sent by you. These errors are generated and sent by Office 365. This is usually alled as DSN which stands for delivery status notification or in simple words bounce messages.
NDR or Non-delivery report is one of the common type of message that you receive which indicates to the user that the email was not delivered.
Error Message
5.7.504 – [email@contoso.com]: Recipient address rejected: Access denied
Error Details
The recipient address that you’re attempting to contact isn’t valid.
Verify the recipient’s email address, and try again.