1. Inventory what must survive the move
List profiles, subscription status, consent evidence, suppressions, bounces, custom fields, lists, segments, forms, templates, automations, transactional messages, integrations and reporting history. Mark which records are authoritative and which historical views cannot be recreated in the new system.
- Export subscribed and suppressed records separately where the source permits it.
- Retain timestamps, source and method for consent.
- Document every custom field and event before mapping it.
- Save a read-only export of campaign and automation performance.
2. Map data and events before importing
Create a field-by-field map between the old and new platforms. For ecommerce, test product, order, checkout, refund and customer events with representative accounts. Importing contacts before the schema is stable creates duplicate fields, broken segments and risky sends.
- Use a small test cohort first.
- Compare counts for subscribed, unsubscribed and suppressed profiles.
- Verify date, boolean and multi-select field formats.
- Confirm how the destination deduplicates contacts.
3. Protect the sending domain
Authenticate the sending domain in the destination platform and verify DKIM and DMARC alignment before campaigns move. Follow the vendor's current guidance for branded sending domains and warming; the required path depends on sending history and infrastructure.
- Do not remove working DNS records until the replacement is verified.
- Send seed tests to major mailbox providers.
- Check the visible From address, reply handling and tracking domain.
- Plan for gradual volume when the vendor recommends warming.
4. Rebuild the revenue-critical journeys
Recreate forms, welcome, recovery, post-purchase, win-back and transactional messages in priority order. Match entry rules, exclusions, delays, frequency controls and exit conditions—not only the copy and design.
- Pause duplicate entry points before enabling the new flow.
- Test every branch with known profiles and events.
- Verify unsubscribe and suppression behaviour end to end.
- Keep screenshots of final settings for the launch record.
5. Run a controlled cutover
Choose a clear cutover time. Stop scheduled campaigns and automated entry in the old platform before enabling equivalent sends in the new one. A short validation window can be useful, but two live systems should not independently message the same audience.
- Reconcile profile and suppression counts immediately before launch.
- Monitor bounces, complaints, unsubscribes and event delays.
- Keep an owner and rollback decision point for the first sends.
- Record every exception rather than fixing it silently.
6. Export, reconcile and retire the old platform
After the agreed validation period, export the final contact, suppression, template and analytics records available from the old platform. Confirm integrations no longer write to it, retain records according to your legal and operational needs, and only then cancel the account.
- Reconcile revenue and conversion reporting across store and analytics data.
- Update privacy documentation and internal procedures where needed.
- Remove obsolete API keys and webhooks.
- Schedule a 30-day review of deliverability and automation results.