Migrate from Blackbaud to Mailchimp

Blackbaud unsubscribe timestamps must map to Mailchimp's suppression list

Mailchimp enforces GDPR and CAN-SPAM compliance at the platform level — contacts marked as unsubscribed in Mailchimp cannot be re-imported as active subscribers without explicit re-consent. Blackbaud's EmailOptOut flag includes an unsubscribe date that must transfer as the Mailchimp 'unsubscribed' timestamp. If your Blackbaud export includes contacts who unsubscribed but whose records were not updated, those contacts may appear active in Mailchimp after import, creating a compliance risk. FlitStack reconciles unsubscribe records against Blackbaud's Constituent Export and sets Mailchimp member status directly via the API, bypassing the standard import flow for suppressed contacts.

Blackbaud SKY API daily quota of 25,000 calls constrains extraction speed

The Blackbaud SKY API Standard Edition throttles at 10 calls per second with a 25,000-call daily quota. For organizations with 50,000+ constituent records and 20+ custom fields each, extracting the full dataset can require multiple days within the quota window. We batch constituent reads (including related tables for custom fields, addresses, and codes) to maximize payload size per call and use exponential backoff on 429 responses. Large migrations may require staged extraction across multiple calendar days, which extends the overall timeline and requires careful delta-capture planning to avoid gaps.

Multiple email addresses per Blackbaud constituent collapse to one Mailchimp contact

Blackbaud supports multiple email addresses per constituent record (home, work, other) each with its own opt-in status. Mailchimp's contact model uses a single email address per member within an audience. We map the primary email address by Blackbaud priority (preferred flag first, then most recently modified) and preserve secondary addresses as a text merge field for reference. The opt-in status of the primary email governs Mailchimp send eligibility; secondary email addresses are informational only.

Blackbaud's constituent hierarchy (households, organizations) requires manual reconstruction in Mailchimp

Blackbaud models household members and organization contacts with relationship types that define roles (Head of Household, Spouse, Employee). Mailchimp has no native household or organizational hierarchy — every contact is a flat subscriber. We preserve relationship data as merge fields and tags, but contacts who should receive household-segmented campaigns (e.g., addressed to 'The Smith Family') must be manually reconstructed in Mailchimp using tags or through a third-party integration that builds household groups from merge field data.

Mailchimp's per-audience field limits require merge field consolidation

Mailchimp permits up to 30 merge fields per audience by default, with additional fields available on higher-tier plans. Blackbaud organizations with 50+ custom field categories across constituents, gifts, and event records may exceed Mailchimp's merge field allowance. We consolidate related fields (e.g., multiple address fields into one combined text field) and flag fields that exceed the destination limit for your admin to prioritize. Low-priority custom fields can be stored as comma-separated text strings within a single merge field.