Migrate from Fat Free CRM to Mailchimp

Database access and schema discovery

We connect to the customer's Fat Free CRM database (MySQL, PostgreSQL, or SQLite) using read-only credentials they provide. We run a schema discovery query to enumerate all tables, columns, join relationships, and any plugin-extended columns before extracting data. The customer provides the database host, port, credentials, and database name. If the database is hosted on the same server as the application, we coordinate access with their hosting provider or DevOps contact.

Data extraction and relationship mapping

We extract all Contacts, Leads, Accounts, Opportunities, Tasks, and tag memberships from the relevant database tables. We run targeted queries to build the join table relationships: contact-account associations from contact_accounts, opportunity-contact links from opportunities_contacts, and campaign-contact memberships from the tag and subscriptions tables. We extract custom field definitions and their serialized values from the custom_fields or extended-column storage. The extraction runs against a read replica or a point-in-time snapshot agreed upon with the customer to avoid impacting production during business hours.

Mailchimp audience and merge field setup

We create the destination Mailchimp Audience via the API and define all Merge Fields before any subscriber import begins. Merge Field names and types are derived from the extracted custom field definitions, with type mapping (TEXT, NUMBER, DATE, ADDRESS, PHONE) based on the data format in the source. If the customer chooses to include Account company names as a Merge Field, we add the COMPANY field. If address data from Accounts is required, we add the ADDRESS merge field. We validate the merge field creation against the Mailchimp API before proceeding to import.

Email validation and subscriber deduplication

We run a validation pass against all extracted email addresses before API insertion. Addresses that fail RFC 5321 format validation are flagged and excluded. We check for duplicate email addresses across Contacts and Leads and consolidate to a single subscriber record (preferring the Contact record when duplicates exist). We also check for unsubscribe flags in the source data and set the appropriate status (unsubscribed or cleaned) in Mailchimp rather than importing as a normal subscriber. The validation report is delivered to the customer before bulk import begins, giving them the opportunity to correct addresses if needed.

Bulk subscriber import via Mailchimp API

We insert subscribers in batches using the Mailchimp Marketing API with up to 5,000 subscribers per batch. Each subscriber record includes the email address, name fields (FNAME, LNAME), merge field values, and tag list. We apply exponential backoff and retry logic on rate limit responses (HTTP 429). We import tags during the subscriber insert by including the Tags array in each batch payload. The import generates a batch operation ID that we track until completion. Row counts are reconciled against the source extraction before the migration is declared complete.

Segment reconstruction from campaign membership

We create Mailchimp Segments corresponding to each Fat Free CRM Campaign based on the campaign-contact membership relationships extracted in step 2. Segments are created as static or dynamic lists using email address inclusion rules. Because Mailchimp Segments are filter-based rather than static lists, we document the segment criteria so the customer can refine them post-migration. We deliver a campaign-to-segment mapping document that lists each source Campaign name, the number of contacts in it, and the corresponding Mailchimp Segment ID and criteria.

Reference exports and admin handoff

We deliver a full CSV export of Opportunities, Tasks, and any unmapped fields as reference files for the customer's records. We deliver the campaign-to-segment mapping document, the email validation exclusion report, and the tag-to-mailchimp-tag mapping. We do not rebuild Fat Free CRM automations, workflows, or plugin-specific features in Mailchimp. We provide a written inventory of any workflow or automation patterns we observed in the source database that the customer should rebuild in Mailchimp Customer Journey Builder. Post-migration, the customer creates their first Mailchimp email campaign, defines automations in Customer Journey Builder, and sets up any new integrations (Shopify, Zapier, or other connected tools) that were not present in Fat Free CRM.