Why aren't my Mailchimp Members linking to Contacts after import?
If Mailchimp Members are syncing to Salesforce but not linking to existing Contacts or Leads, the issue is usually a mismatch between your Field Mappings and Matching Rules.
The Problem
When you map an email field (like Personal Email or an NPSP email field) as the primary email in Field Mappings, the system must also be able to query that field during the sync to find matching Salesforce records. This is configured in Matching Rules.
Common scenario:
- You map Personal Email (npe01__HomeEmail__c) in Field Mappings → Salesforce to Mailchimp
- But you haven't added Personal Email to your Matching Rules
- Result: Members import but Contact lookups remain empty ❌
Why This Happens
The integration needs to query the email field you're using for two purposes:
- Field Mapping - to know which email to sync between systems
- Matching Rules - to deduplicate and find existing Salesforce records during sync
If the field isn't in Matching Rules, the system can't query it for deduplication, which prevents proper linking.
How to Fix It
Step 1: Go to your audience's Mappings settings (Mailchimp to Salesforce direction)
Step 2: Review the Matching Rules section (top of the page)
Step 3: Add all email fields you're using in your mappings to the Matching Rules
Step 4: Save and run the next scheduled sync
How to Verify the Fix
Check Maintenance logs for errors like:
- MC4SF_RULE_EXCEPTION: Unable to Process Rules. Missing queried field: Contact.npe01__HomeEmail__c
These errors should stop after the next successful sync.
Important Notes
- NPSP users: Be especially careful with Personal Email vs standard Email field
- The email field used in Field Mappings must exist in Matching Rules
- This applies to any custom email fields, not just NPSP
