In Microsoft Dynamics CRM 2015 for Outlook or later, you can view the appointments, contacts, and tasks fields that are synchronized between Dynamics 365 and Outlook so you can see where the data is coming from. You can also determine whether the fields:
Are synchronized one way (from Outlook to Dynamics 365 or from Dynamics 365 to Outlook)
Are synchronized two way (from Outlook to Dynamics 365 and from Dynamics 365 to Outlook)
For example, if the fields are synchronized one way, from Dynamics 365 to Outlook, you can update the field in Outlook and save the change, but your changes won’t be synced with Dynamics 365, and will be overwritten if the same field value is changed in Dynamics 365. So if fields are synced one way, there’s no need to change the value in the synchronized field.
View the synchronized fields
In Dynamics 365 for Outlook, click File, and then click Dynamics 365.
On the Synchronize button, click the down arrow, and then click Review Synchronization Settings.
In the Synchronization Settings for Outlook or Exchange dialog box, click the Synchronization Fields tab.
In the Entity Type list, select the record type you want to view.
Outlook fields are displayed on the left and the corresponding Dynamics 365 fields are displayed on the right. The blue arrows show the sync direction:
This indicator Shows that the fields Are synced one way from Outlook to Dynamics 365 Are synced one way from Dynamics 365 to Outlook Are synced two way Aren’t synced
Field synchronization direction can be impacted by security settings configured by your system administrator. For example, if you don’t have read privileges for a field, it won’t be synchronized in Outlook even if the field is configured for two-way synchronization. To determine whether you have read privileges for a field, click the View in Dynamics 365 button to open the record in Dynamics 365. If you see the Lockicon, you can’t access the field.