Whenever an email is sent to a mail-enabled public folder, the sender receives an non-delivery receipt with an error like
Remote Server returned ‘550 5.7.1 RESOLVER.RST.NotAuthorized; not authorized [Stage: CreateMessage]’
In order for a public folder to receive email, the folder must allow Anonymous users to create items.
- Log in to your O365 management console, switch to the Exchange admin center > public folders. Navigate to the folder bouncing messages and verified that it is mail enabled.
- With the problem folder selected, edit the folder permissions.
- Make sure you have Owner permissions on the folder, then save the changes.
- In Outlook, switch to the “Folders” view and expand the Public Folders down to the problem folder. Right click and choose Properties. On the Permissions tab, make sure that the “Anonymous” user as “Contributor” rights. Click OK to save your changes.
At this point, messages should no longer bounce from the PF.