Only the folder you select will be tracked. You can only track folders or subfolders inside your Exchange Inbox. In the Folder-Level Tracking dialog box, under Exchange Folder, click + New Folder Mapping, click the down arrow in the box that appears, and then select the folder you want to track. In the Set Personal Options dialog box, click the Email tab, and then under Select the email messages to track in Dynamics 365 for Customer Engagement, click Configure Folder Tracking Rules. In Dynamics 365 for Outlook: Click File > Customer Engagement > Options. In the web app: On the nav bar, click Options. For admin information about setting up server-side synchronization, see Set up server-side synchronization of email, appointments, contacts, and tasks If you don’t know which synchronization method your organization uses, contact your Dynamics 365 apps administrator.

Your organization must use server-side synchronization as your email synchronization method. For admin information on enabling tracked folders, see Configure Outlook or Exchange folder-level tracking For more information, contact your Customer Engagement administrator. The tracking folders feature must also be enabled by your administrator. Interested in getting this feature? Find your Dynamics 365 administrator or support person

This feature was introduced in Dynamics CRM Online 2015 Update 1 and CRM 2016 (on-premises). For example, set up an Exchange rule that automatically routes email from a Contoso contact to a tracked Contoso folder, which is linked to a specific Contoso opportunity. This makes it easy to automatically route email messages to a particular folder. Tracked folders work with Exchange Inbox rules.

How to set up folders in outlook mail