Inventory before exporting
Record active, unsubscribed, bounced, complained, and suppressed contacts; fields; groups or tags; segments; forms; templates; automations; domains; integrations; reports; and legally important consent records. Identify what must move, what should be archived, and what should be retired.
Do not export only active addresses and forget suppression state. A migration that accidentally makes an unsubscribed person marketable again is a serious failure. Keep the old platform available through the first verified campaigns so unsubscribe history, suppression evidence, templates, automations, and performance baselines remain recoverable during the cutover window.
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Start a 14-day MailerLite trial →Clean and map the data
Remove duplicates and invalid records using a documented process, preserve original consent evidence, and map every source field to a MailerLite field or explicit archive. Decide how old tags translate into groups, fields, or segments. Use UTF-8 and a single-sheet structure where the official import guidance requires it.
Create a mapping table and have another person review the fields that control personalization, eligibility, or automation.
Run a staged import and journey test
Import a small consented segment, review accepted and rejected records, verify group membership, and choose carefully whether group-linked automations should trigger. Test confirmation, preference, unsubscribe, and the hardest automation. Authenticate the domain and send representative messages before moving the full audience.
Compare counts with the old platform and explain every material difference rather than forcing totals to match.
Cut over with rollback
Choose a low-risk window, pause conflicting sends, update forms and integrations, run the final delta import, and monitor delivery, bounces, complaints, automation entry, and support. Keep the old account and exports available until all critical paths and suppression records are reconciled.
Document the cutover timestamp, owner, known gaps, and rollback condition. A clean migration ends with a simpler operating model, not two partially active systems. A migration can begin inside MailerLite's 14-day trial, which includes live chat and email support for those 14 days.
Sources used for this page
These records support the facts and comparisons above. Merchant-controlled records are labeled so you can separate product claims from independent evidence.
- MailerLite migration resources — Merchant documentation · mailerlite.com · Merchant-controlled · read August 23, 2026
- MailerLite subscriber import guidance — Merchant documentation · mailerlite.com · Merchant-controlled · read August 23, 2026
- MailerLite domain authentication guidance — Merchant documentation · mailerlite.com · Merchant-controlled · read August 23, 2026
- MailerLite plans and pricing — Merchant documentation · mailerlite.com · Merchant-controlled · read October 6, 2026
- MailerLite product overview — Merchant documentation · mailerlite.com · Merchant-controlled · read October 6, 2026