Deleting a public folder in MDaemon Connector means Outlook renames the folder to be a subfolder of the Deleted Items folder.
MDaemon doesn’t allow IMAP folders to be renamed when crossing public and private folder boundaries and so the deletion fails, typically with “A resource is busy or you lack sufficient permissions error” even though you have full permissions to that folder and its parent folder.
There are a few ways to perform this delete operation despite this:
1. When selecting delete hold down SHIFT on the keyboard. This will cause Outlook to permanently delete the Public Folder and as it won’t try and move it to the Deleted Items folder the same issue will not occur. It’s important to note that there is no way to recover this folder from Outlook when this step is taken, though.
2. Login to Webmail and delete the folder from there.
3. In the MDaemon Interface at Setup -> Public Folder Manager select the folder and choose ‘Delete Folder’.