We came across an interesting issue with the Dynamics 365 Email Router. We had set up the router for incoming emails using a Queue and everything was working fine until a few days ago when we saw the following error in the Event View on the Email Router server.
At least one system user or queue in the organization must be a recipient
It turns out that this is due to the security set up. We changed the Owner of the Queue to a System Administrator user and the emails started flowing into CRM. We didn’t want to change the Owner though, so we needed to add the following security permissions to the existing Queue Owner.
• Organization Read of Queue
• Organization Append of Queue
• Organization Append To of Queue
• Organization Read of Mailbox
• Organization Read of Team
• Organization Read of User
• User Create, Organization Read, User Write, Organization Append, Organization Append To of Activity
This should help you get past this strange error.