Dynamics 365 App for Outlook is an Exchange EWS call service (add-in) which deliver the functionality to track emails, appointments, contacts, and tasks within your Outlook client. This functionality is different than the synchronization of the records from CRM to Outlook with using server-side synchronization and both features are presenting similar functions but with difference between direction of the synchronization – CRM to Outlook and vice versa. For our specific case, when you track and set regarding an email in OWA/Outlook with using Dynamics 365 App for Outlook, and if you change the set regarding manually from Dynamics 365 CE the regarding changes are not changed in OWA/Outlook for Dynamics 365 App for Outlook during the next synchronization cycle. This is a design limitation that we want to be added.