The Outlook add-in allows you to email links to files and folders using your Microsoft Outlook application. As an added benefit, the Outlook add-in keeps track of the items that you have shared by automatically creating and populating a Shared Items folder in your Synced Folder.
In some instances, however, you might encounter the following error message when attempting to send files using the Outlook add-in: Can't process cloud attachments. Error: This email was already sent. Please discard the message, create new and try again.
In most instances, this error is caused when the Shared Items folder does not exist.
To correct this issue:
From the desktop client, navigate to the Synced Folder location (for example, C:\Users\UserName\SyncedFolder).
Manually create a new folder titled, Shared Items.
Note: Alternatively, this process can be completed from the web portal. Additionally, administrators can remotely support users by navigating to the user's account from the Accounts tab in the administrative web portal.