Hello guys,

In a customers CRM there is an Email Router set up in order to receive email in the CRM portal.

The error i am getting in the event viewer is something like this: 

"#9628 - An error occurred while delivering the email message with subject "subject" in mailbox test@test.com for delivery to http://crmsrv/CRMORG. System.ServiceModel.FaultException`1[Microsoft.Xrm.Sdk.OrganizationServiceFault]: You cannot add items to an inactive queue. Select another queue and try again. (Fault Detail is equal to Microsoft.Xrm.Sdk.OrganizationServiceFault). "

The queue that receives incoming emails from the specified mailbox is active and receives emails.

The business logic of the customer is once the email is delivered to a linked queue it is transformed into a case based on some rules.

The problem in this is that multiple users use the outlook client and sometimes delete emails.

After contacting the customer, i asked them to find the specified by the error subject of the email but they could not find any emails with this subject.

I am guessing that the Email Router fails to process the email once deleted.

Is the above practice valid? Should users use the outlook client and delete emails or should they delete emails from the CRM portal? Are my assumptions correct?
Is there any kind of a guideline in such cases?