Hello,

We are on CRM 2013 on-premise. We are using the CRM email router to automatically create email activities for every email that arrives in a shared group mailbox. 

In the Mailbox setting, we set the option to 'Delete Emails after Processing' so that to avoid build-up of emails in Exchange.

However the emails are never deleted from Exchange Online.

Any idea why the emails are not being deleted?

Thanks.