I am getting an error from my mobile email client due to an invalid folder name. The error is: One or more folders in your mailbox is named incorrectly. The name of one or more of your folders includes the character "/" or more than 250 characters. Folders with names that include this character can't be downloaded to your IMAP e-mail program. Please rename these folders:
DR / BC (Deleted Items/DR / BC)
This folder no longer exists (and has not for more than 30 days). Some other solutions advise going into Office 365 OWA, right-clicking on 'Deleted Items' and choosing Restore. But that option does not appear. In the Outlook desktop client, right-click on 'Deleted Items' offers 'Recover Deleted Items' but they are just the messages, not the folder name.
Is there some other way to view and permanently delete this folder name? It is causing...