Duplicate Messages in Outlook Desktop

When users move items from their primary email account through Outlook Desktop, into their Online Archive or another shared mailbox that they have automapped to their Outlook profile we are seeing that Outlook will make a copy of the email, move the message to the intended folder and then permenately delete the original email message. Assuming this is intended behavior in case there is an issue with the original email during the time the item is moving from one account to another.

Issue is that when users are bulk cleaning up items from one account to another or are under litigation hold, this causes a ballooning of the data until the data is automatically purged.