How to Migrate From MailerLite Without Losing Data

Migrating from MailerLite without losing data comes down to exporting everything while your account is still active, then rebuilding in a fixed order: contacts and custom fields first, then groups as tags and segments, then suppression records, templates, automations, forms, and finally domain authentication. The order matters because groups and segments reference contacts, and your sending domain has to be verified before the first real send. If you rush the suppression step, you will email people who opted out, which is the one mistake that actually damages your sender reputation.

What you'll set up and what you need

Before you touch anything, build a migration inventory. You are moving seven things:

1. Contacts and custom fields — the subscriber records plus every field you use for personalization.
2. Groups and segments — your static groupings and any dynamic rules.
3. Unsubscribe and suppression records — unsubscribes, hard bounces, complaints.
4. Templates — your saved email designs.
5. Automations — every live workflow with its trigger, waits, conditions and emails.
6. Signup forms — embeddable forms plus the consent records behind them.
7. Domain authentication — DKIM, SPF and DMARC for your sending domain.

Gather these before you start: your MailerLite login, CSV exports of subscribers and groups, DNS access for your sending domain, and a written list of every live automation and form. The automation list is easy to forget because automations run quietly in the background.

One timing note: MailerLite's paid plans give every paid plan the full feature set and charge more only for a bigger list or more sending (verified 2026-11-07 on mailerlite.com/pricing). Export while your account is active, then cancel once the new setup is verified.

If you are moving to Mailerflow, the platform handles CSV import with duplicate and validity checks, custom fields and tags, and offers free migration help (contacts, suppression lists, templates, core automations) on eligible paid plans. That help covers the fiddly parts — suppression lists and core automations — rather than the whole project.

Step-by-step: migrate from MailerLite in order

Each step below has the action, what you should see, and a verification check. Menu labels may differ between accounts, so check MailerLite's official docs for the exact current wording. If you are still deciding whether the move is worth it, the comparison of MailerLite alternatives is a useful gut-check before you start exporting.

1. Export your contacts and custom fields

In MailerLite, export subscribers to CSV and make sure the export includes all custom fields, not just email and name. Open the file and confirm you have columns for email, name, every custom field, subscription date, and status. MailerLite's export is your source of truth — do not hand-edit it beyond column mapping.

In Mailerflow, run the CSV import. The importer checks for duplicates and invalid addresses before anything lands, then you map columns to custom fields and tags.

Verify: compare the imported contact count against the export row count. They should match minus any duplicates the importer flagged. Spot-check three contacts with unusual field values (a date field, a number field, a long text field) to confirm nothing shifted columns.

2. Recreate groups as tags or segments

Export each group separately, or export the group column alongside your contacts. Then recreate them in Mailerflow as tags and build dynamic segments on fields, tags, engagement, events and website behavior.

The conceptual difference is worth understanding: a MailerLite group is a static list you add people to by hand or by rule. A tag plus a segment is more flexible — the tag records what happened, the segment decides who currently qualifies. A "webinar attendees" tag plus a "tagged webinar attendees AND opened in last 90 days" segment gives you a live audience that updates itself.

Verify: open one segment and confirm the count matches the original group count. If it does not, the difference is usually contacts who were in the group but are now unsubscribed or bounced.

3. Bring unsubscribe and suppression records across

Export unsubscribed contacts and any bounce or complaint suppression list. Import them as a suppression list before your first campaign. This is the step people skip, and it is the one that generates spam complaints.

Mailerflow automatically suppresses bounces and complaints going forward, and free migration help covers suppression lists on eligible paid plans — but historical unsubscribes still have to come from your MailerLite export.

Verify: send a test campaign to a small seed list that includes one suppressed address. Confirm the suppressed address is blocked and does not receive the send.

4. Rebuild templates

Export or screenshot your MailerLite templates, then rebuild them in Mailerflow's visual block editor — headings, heroes, products, columns, social links — and save each as a reusable template. If a template was only ever used once, skip it and rebuild from scratch instead.

If you would rather not rebuild by hand, describe the email in the AI email builder and get a complete responsive design, subject lines and preview text, then adjust the blocks. That is usually faster for simple newsletters and slower for heavily customized designs.

Verify: send a test to yourself and open it in a mobile client and a desktop client. Check that images scale, columns stack, and the footer links work.

5. Recreate automations

List every live automation with its trigger, waits, conditions and emails — write it out as text before you cancel anything. Rebuild the core ones first: welcome, abandoned cart, re-engagement. Long-tail automations can wait a week.

In Mailerflow you can describe a workflow in a sentence and the AI automation builder drafts it (trigger, waits, conditions, emails) for review before activation, or build it visually with waits, conditions, webhooks and AI steps. Either way, nothing goes live until you approve it.

For a deeper walkthrough of this specific step, the automation rebuild checklist covers triggers, timing and testing in more detail.

Verify: run one test contact through the welcome automation and confirm each step fires in order with the right delays.

6. Move signup forms and consent records

Recreate your embeddable signup forms with double opt-in and consent records in Mailerflow, then update the embed code on your site and any landing pages. Consent records matter if you are subject to GDPR — you need to show when and how someone opted in.

Verify: submit a real test signup, confirm the double opt-in email arrives, click it, and check the consent record is stored against the contact.

7. Authenticate your sending domain

Add your sending domain in Mailerflow and follow the guided DKIM, SPF and DMARC setup with automatic verification. Keep the MailerLite DNS records in place until the new domain is verified, then remove them. Removing them early breaks sending from the old platform while you still need it for the parallel send.

Verify: check the domain shows verified in Mailerflow, send a test to a Gmail address, and inspect the headers for a DKIM pass.

8. Run a parallel send, then cancel MailerLite

Send one campaign from Mailerflow to a small segment, then compare delivery and click numbers against the same campaign sent from MailerLite. If the numbers look comparable, move the full list. Only cancel MailerLite after the parallel send looks right and you have exported everything you need.

Verify: confirm the MailerLite account is cancelled and no billing continues.

A worked example: a 4,200-contact list with three automations

This is an illustrative example, not a real customer.

A small online course business has 4,200 contacts, 6 custom fields, 9 groups, 2 templates, a welcome automation and an abandoned-cart automation. Here is how the migration runs:

• Export and import. The subscriber CSV has 4,200 rows. Mailerflow's import flags 40 duplicates (people who signed up twice with different capitalization) and merges them, landing 4,160 contacts. The 6 custom fields map cleanly; the "last purchase date" field needs its format checked because MailerLite exported it as text.
• Groups to tags. The 9 groups become 9 tags, and three of them get segments layered on top — for example, "course buyers" tagged, then a segment for buyers who have not opened in 60 days.
• Suppression. 310 unsubscribes and 22 hard bounces are imported as a suppression list before any campaign goes out.
• Templates. Both templates are rebuilt in the block editor in under an hour, since they were simple two-column newsletter layouts.
• Automations. The welcome sequence (5 emails) and abandoned cart (3 emails) are rebuilt and tested with a single test contact each.
• Domain. DKIM, SPF and DMARC are added, verified, and only then are the MailerLite records removed.

In this illustrative scenario, the data work would take roughly an afternoon and automations and testing another session. Treat that as a rough range, not a benchmark — a list with 40 custom fields and 30 automations takes considerably longer.

How to check it works

Run these as pass/fail checks in one sitting:

Common mistakes and fixes

Importing unsubscribes as active contacts. This is the worst one. Fix: always import unsubscribes and bounces as a suppression list first, before the main contact import.

Forgetting custom fields, so personalization breaks. A template referencing {{first_name}} or a purchase date silently renders blank. Fix: map every field during import and spot-check three contacts before sending.

Rebuilding automations without testing the trigger. The workflow looks right but never fires. Fix: push one test contact through each automation and watch every step.

Removing MailerLite DNS records before the new domain is verified. Sending breaks on both platforms. Fix: keep both sets of records until Mailerflow shows the domain verified.

Cancelling before the parallel send. You lose access to your export and your comparison baseline. Fix: cancel last, after the parallel send looks right.

Importing a CSV with duplicate rows. Counts inflate and people get emailed twice. Fix: let the importer's duplicate check run and review what it flags rather than overriding it.

Where MailerLite is strong, and who each option suits

All competitor facts below were verified on 2026-11-07 on mailerlite.com/pricing.

MailerLite's paid plans give every paid plan the full feature set, and paid plans charge more only for a bigger list or more sending. Yearly billing saves 10%. The Comfort plan is positioned for sending regular newsletters and running automations, and includes 50 automations, 10 forms, 10 sites, 5 digital products and email support. The Power plan is positioned for frequent senders, teams and AI agents, and includes unlimited monthly emails, unlimited automations, forms, sites, digital products, user seats, templates, integrations and campaigns, multiple automation triggers, full MCP and API access, live chat and email support, and a free trial with no credit card required.

MailerLite suits people who want a simple, well-designed tool where every paid plan is complete.

Mailerflow, for comparison, offers CSV import with duplicate and validity checks, custom fields and tags, and free migration help (contacts, suppression lists, templates, core automations) on eligible paid plans. Every paid plan includes unlimited emails. There is a Free plan with 2,500 contacts and 10,000 emails a month, and paid plans from $14.90/month. The AI email builder turns a description into a complete responsive design with subject lines and preview text. Data is hosted in Europe, and yearly billing costs the same as 10 months.

If you are weighing other platforms too, Mailchimp offers a 14-day free trial of the Standard plan, which starts at $20 per month and allows up to 6,000 emails each month (verified 2026-11-07 on mailchimp.com/pricing/marketing). Brevo offers a free forever plan with no credit card needed, and its Starter plan includes from 5,000 emails per month (verified 2026-11-07 on brevo.com/pricing). EmailOctopus offers a free Starter plan with 2,500 subscribers and 10,000 emails per month, and its Pro plan costs $9 per month billed yearly (verified 2026-11-07 on emailoctopus.com/pricing). ActiveCampaign offers a 30-day money-back guarantee, and its Plus plan includes 1,000 contacts, 10,000 email sends per month and 1 user seat (verified 2026-11-07 on activecampaign.com/pricing).

For a fuller breakdown of how these stack up, see the MailerLite pricing explainer and the ActiveCampaign comparison.

Next steps

If you are still in MailerLite and weighing whether to leave, the Classic vs current MailerLite breakdown is worth reading first. For a step-by-step walkthrough of the export itself, see the MailerLite alternatives comparison, which includes a section on exporting contacts and custom fields.

FAQ

Can I migrate from MailerLite for free?

MailerLite's own export is free — it is a CSV download from your account. On the destination side, Mailerflow offers free migration help (contacts, suppression lists, templates, core automations) on eligible paid plans. Check the official page for current eligibility.

Will I lose my unsubscribes?

No, as long as you export them and import them as a suppression list before your first campaign. If you skip this, you will email people who opted out, which generates complaints and hurts deliverability.

Do I need to keep MailerLite active during migration?

Yes. Keep it active until the parallel send is done and you have confirmed the new setup works. Cancelling early cuts off your access to exports and your comparison baseline.

Can I keep my sending domain?

Yes. You re-authenticate the same domain in the new platform by adding its DKIM, SPF and DMARC records. Keep the MailerLite records in place until the new domain shows verified, then remove them.

How long does it take?

It depends almost entirely on how many automations and custom fields you have. A small list with two or three automations is a focused afternoon plus a testing session. A large list with dozens of automations and complex segmentation takes considerably longer — plan for multiple sessions rather than a single sitting.

Try Mailerflow on the Free plan (2,500 contacts, 10,000 emails a month, AI automation builder included), import your contacts by CSV, and ask about free migration help on eligible paid plans.