New features which are now rolled out for all Dynamics 365 to Mailchimp subscribers are:
1) Sync Dynamics marketing lists to Mailchimp Groups
2) Update Dynamics CRM from Mailchimp contact update forms
For this to take effect. The webhooks must first be established initially by syncing first the records from CRM to Mailchimp.
1. In Step 1 of the Sync Profile, sync all records from CRM to Mailchimp or you may also use the specific Marketing Lists sync if preferred. Hit the "Next" button at the very bottom to move to the next step.
2. In Step 2 of the Sync Profile, enter the Main Audience. Then enable the option " Update Dynamics 365 if subscribers update their profiles in Mailchimp " to enable the webhooks.
What is a Webhook? Mailchimp uses Webhook technology to update the records in CRM in realtime even if the sync in SyncApps s not running. See the flowchart below:
Once done, hit Save then Reset Sync Process and resync so that SyncApps will follow the new configuration on the next syncs.