We are currently syncing contacts to mailboxes and have some conditions where users can add a contact to a marketing list, and thus get the contact owned by another user pushed to their Outlook contacts. We are also using the native Exchange online integration on iOS (not the Outlook app) to sync contacts to the mobile device.
What now happens frequently is that user merge contacts on their iPhones with some contacts they have locally on their devices and thus updating a Dynamics synced contact from their phone. This change in then propagated to Dynamics, and then to all other users who sync that contact.
I want to prevent this changes from propagating, and also teach the users to make changes only in Dynamics. And, I also want to prevent accidental changes from happening, when users use some deduplication or merging functionality on their phones.
How do I make sure that Dynamics is the leading system here?