Hello I am interested if someone knows a way to synchronize with custom entity created, other then this Settable syncs by field in Dynamics 365 Customer Engagement (on-premises) | Microsoft Docs 8 entities that are mention in the documentation.
I think this is a design limitation.
You can synchronize only Emails, Appointments, Contacts and Tasks from CRM to Outlook and the reason behind this is that for a custom entity, the application wouldn't know what to map it against.
I see two workarounds:
I would like to correct an earlier response that listed just a few entities that can be synced with Outlook. Here is the full list:
The Letter and Fax entities are so rarely used, that they might be a good candidate for your custom functionality.
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