For information on setting up Mailchimp for the first time, check out this guide.
Contacts Missing in Mailchimp
When importing Contacts to Mailchimp, you need to set which Company Types and Contact Roles for the contacts you want to be synced. The number of contacts shown that fit the Company Type and Contact Role criteria also includes those who are 'Unsubscribed', which means their Email Flag is set to 0.
These unsubscribed Contacts won't be imported in the first import, but will be brought in with subsequent imports if they've been updated. For Contacts to be imported in the first run, their Email Flag should be set to 'Yes'.
After the initial import, subsequent syncs will run every 15 minutes. This will get a list of CRM Contacts that have been updated since the previous import, and then update/create these in Mailchimp. If an unsubscribed Contact has been updated, it'll be imported to Mailchimp, but will be marked as Unsubscribed.
When a contact is updated in MailChimp via an Admin or User action, this will trigger a webhook to then update that contact in the CRM. Currently there is no handling for contacts being updated in MailChimp via an API action such as a third party integration (Shopify).
The CRM will also filter out Contacts if they don't have an email address.
Contact Synchronisation
When a CRM Contact is created in Mailchimp or is linked to an existing Mailchimp Contact, there are certain CRM fields that we will be populated in Mailchimp. The fields below are CRM fields which should be reflected in Mailchimp:
Contact Primary Email Address
Contact Email Subscription Status
Contact First Name
Contact Last Name
Contact Role
Contact Industry
Company Name
Company Group Name
Company Type
Order Warning Days
Company RFM Categorisation
Company Account Manager Name
Company Account Manager Email