Outlook Tracking Deactivated Contact Records

Hi,

We're running Dynamics On Premise, and are currently having an issue with users trying to track incoming emails through Outlook.

If a Contact has been previously been merged in the CRM, and users attempt to track an incoming mail in Outlook from the Contact, the CRM is picking up the the deactivated record, despite there being an active Contact in the CRM with the same email address.

Any help would be much appreciated.

Thanks.