MC4SF_MEMBER_INACTIVE_SKIP

What this means: A Salesforce change was not sent to one or more Mailchimp members because Mailchimp does not accept that update for their status. This applies to Cleaned members (no profile or email changes), Archived members, and Unsubscribed members when the email address would change. Merge field updates to Unsubscribed members still go through.

Common causes: Editing or merging Salesforce Contacts or Leads that are linked to inactive Mailchimp members.

What to do: Usually nothing. The Mailchimp membership is unchanged and the message lists the affected email addresses. To use a new email address for one of these people, add it to the audience as a new contact via Manage Members or the Data Wizard.