Migrate from Function 365 to Mailchimp

Each Microsoft 365 Contact becomes a Mailchimp Member within the target audience. Email address is the unique identifier used for matching. If the same email exists in multiple source lists, FlitStack flags duplicates before insert and applies your preferred de-duplication rule.

Primary email maps directly to Mailchimp's member email address. Microsoft 365 allows multiple email addresses per contact; the primary emailaddress1 becomes the member address and secondary emails are preserved as merge fields.

Microsoft 365 stores address as a composite string and as individual component fields. FlitStack decomposes the composite into Mailchimp's structured address merge fields so conditional content (e.g., city-based targeting) works correctly after migration.

Microsoft 365's opt-out flag maps to Mailchimp's member status. optout = true becomes unsubscribed; optout = false with GDPR consent fields present becomes subscribed. We flag records where Microsoft 365 consent is absent to trigger re-permissioning in Mailchimp before campaigns send.

Each Dynamics 365 marketing list becomes a Mailchimp segment within the target audience. Segment conditions are translated to Mailchimp filter logic so the same audience slice receives targeted campaigns. Segments are activated post-migration to avoid sending to unverified contacts.

All Microsoft 365 custom properties and Dynamics 365 custom fields are created as Mailchimp merge fields with matching data types. Date fields use Mailchimp's DATE type, numbers use NUMBER, pick-lists become dropdown merge fields. Fields exceeding 255 characters are truncated with a note, or stored as a member note for reference.

Lead status, opportunity roles, and account segment tags from Dynamics 365 are mapped to Mailchimp member tags. Tags preserve the role taxonomy so you can re-target 'Decision Maker' contacts or 'Closed Won' customers with role-specific campaigns after migration.

Historical campaign sends, opens, and clicks from Dynamics 365 are preserved as custom merge fields for reporting continuity. Mailchimp's own engagement tracking replaces Dynamics 365 campaign analytics going forward; FlitStack stores the source record ID so historical data can be joined in a BI tool if needed.

Microsoft 365's original contact creation date is preserved as a custom merge field (ORIGINAL_CREATE_DATE) on each Mailchimp member. Mailchimp's own Stats.StartDate reflects the migration date; the custom field maintains historical reporting continuity for age-of-contact analysis.

Microsoft 365 and Dynamics 365 company/account records are stored as a merge field (COMPANY_NAME) and optionally as a tag on each related member. Mailchimp has no native account object; the tag approach allows company-based segment filtering without creating a separate accounts table.

Microsoft 365 contacts without a valid email address cannot become Mailchimp members and are exported to a review CSV with full contact details. FlitStack preserves the record so your team can obtain a valid address and re-import manually post-migration.

Microsoft 365 marketing workflows and Dynamics 365 customer journeys do not transfer to Mailchimp. We export the workflow definitions — trigger conditions, step logic, wait periods — as a structured reference document your team uses to rebuild equivalent Automation Flows in Mailchimp after cutover.