How to Migrate From Mailchimp: A Step-by-Step Plan

You migrate from Mailchimp by exporting four things — your audience, your tags and segments, your suppression data (unsubscribes, cleaned addresses, complaints) and your sending authentication — then importing them into the new platform, rebuilding templates and automations by hand, and authenticating your domain before the first send. Nothing about that is technically hard, but the order matters: if you import contacts before suppression lists, you risk emailing people who opted out.

This guide walks through the full sequence with the exact Mailchimp screens, what to click, and how to confirm each step worked. It assumes you have already decided where you are going; if you have not, the comparison section near the end covers the practical differences between the main options.

What you'll set up and what you need before you start

Four things must survive a migration intact:

1. The audience, including every custom field. A "first name" column is easy; a "last purchase date" or "loyalty tier" field is what your segmentation depends on.
2. Tags and segments. Tags are labels you applied; segments are rules. Tags usually transfer as tags, but segments almost always need rebuilding as dynamic rules in the new platform.
3. Suppression data. Unsubscribes, cleaned (hard-bounced) addresses and abuse complaints. This is the part people skip, and it is the part that gets domains blocked.
4. Sending authentication. Your domain, plus DKIM, SPF and DMARC records in DNS. If you authenticated mail.yourdomain.com in Mailchimp, you will authenticate it again in the new platform.

Templates and automations are almost always rebuilt rather than transferred. Budget real time for that — it is usually the longest part of the project, not the export.

Gather these before you start:

• Mailchimp login with permission to export (Owner or Admin).
• Access to your DNS provider for the sending domain.
• A spreadsheet editor that handles CSV without mangling dates.
• A decision on the destination platform.

If you are moving to Mailerflow, its CSV import runs duplicate and validity checks and maps custom fields and tags, and free migration help covering contacts, suppression lists, templates and core automations is available on eligible paid plans. That is worth asking about before you start hand-mapping columns.

One caution on Mailchimp's side: plans, contact tiers and send limits change, so check the current numbers on Mailchimp's official pricing page rather than trusting a screenshot from last year. The figures quoted in this article were verified on 2026-11-09 on mailchimp.com/pricing/marketing.

Step-by-step: how to migrate from Mailchimp

1. Audit the account before exporting anything

Go to Audience > All contacts and note the total contact count. Then open Audience > Settings > Contact fields and write down every custom field and its type (text, number, date, dropdown). Finally, check Audience > Tags and Audience > Segments and list them.

Verify: your written list should account for every field and tag you actually use. Anything you cannot name a use for, drop now rather than importing clutter.

2. Export the audience

Go to Audience > All contacts > Export Audience. Choose the CSV option intended for another application (Mailchimp labels this clearly in the export dialog). Mailchimp emails you a download link when the file is ready — it is not instant for large lists.

Verify: open the CSV and confirm the row count matches the contact count from step 1, minus any rows Mailchimp excludes.

3. Export suppression data separately

This is the step that protects your sender reputation. In Audience > All contacts, filter by status and export each of these as its own CSV:

• Unsubscribed
• Cleaned (hard bounces and addresses Mailchimp stopped sending to)
• Archived, if you have any

Verify: the three files together should explain the gap between your total audience and your subscribed count. If the numbers do not add up, you have missed a status.

4. Clean the CSV before importing

Open the export and delete Mailchimp's internal columns — member rating, opt-in IP, latitude/longitude, the various MEMBER_RATING-style fields you will never use. Keep:

• Email address
• First and last name
• Your custom fields
• Tags
• The original opt-in timestamp (this is your consent record — do not discard it)

Standardise date formats to ISO (YYYY-MM-DD) so the destination platform parses them correctly, and remove exact duplicate rows.

Verify: sort by email address and scan for duplicates. A list of 6,000 rows should not contain 6,000 unique-looking addresses with three near-identical variants.

5. Import into the new platform

In Mailerflow: Contacts > Import CSV, map each column to a field, create any missing custom fields inline, map your tag column, then run the duplicate and validity check before confirming. The check flags malformed addresses and existing contacts so you do not double-count.

Verify: the import summary should report imported, skipped-duplicate and invalid counts that add up to the file's row count.

6. Recreate tags and segments

Tags usually come across with the import. Segments do not — rebuild them as dynamic segments based on fields, tags, engagement or events. A Mailchimp segment like "clicked in last 30 days AND tag = wholesale" becomes a rule in the new platform, not a static list.

Verify: open each new segment and confirm the member count is in the same ballpark as the old one. Small differences are normal; a 40% gap means a rule is wrong.

7. Rebuild templates

Exported Mailchimp HTML is table-based and rarely pastes cleanly into any modern editor, so plan to rebuild. Either rebuild in the visual block editor or, in Mailerflow, describe the email to the AI email builder and get a complete responsive design plus subject lines and preview text as a starting point, then adjust.

Verify: send a test to yourself and check it in Gmail, Outlook and on a phone. Outlook is where table-based layouts usually break.

8. Rebuild core automations

Write each automation out as a plain-language flow first: trigger, waits, conditions, emails. A welcome series with three emails and two waits becomes a trigger on signup, a wait of two days, an email, a wait of three days, an email, and a conditional branch on whether the contact clicked.

In Mailerflow, the AI automation builder drafts that workflow from a sentence for you to review before activation. Whatever platform you use, do not activate until you have read every step.

Verify: trigger the automation with a test contact and watch each step fire in order.

9. Authenticate the sending domain

Add DKIM, SPF and DMARC records at your DNS provider. Mailerflow guides the setup and verifies the records automatically; other platforms do the same with their own record values. Never copy DNS values from one platform to another — they are unique per account.

Verify: send a message to a Gmail and an Outlook address and inspect the raw headers. You want dkim=pass and spf=pass.

10. Warm up and test

Send your first campaign to your most engaged segment, not the whole list. Watch bounce and complaint rates on the first two sends and pause if they spike.

11. Run in parallel, then cancel

Keep Mailchimp live for one or two sends as a fallback. Mailchimp lets users cancel or downgrade to Essentials or the basic Free plan at any time (verified 2026-11-09 on mailchimp.com/pricing/marketing), so you can step down rather than cutting over cold.

A worked example: a 6,400-contact list with three automations

The following is an illustrative scenario, not a customer story.

A small online store has 6,400 contacts, 11 custom fields, 14 tags, a three-email welcome series, an abandoned-cart flow and a re-engagement flow.

Export phase (about two hours). The audience export returns 6,400 rows. The unsubscribed export returns 810, cleaned returns 240, archived returns 95. That accounts for the difference between the total and the 5,255 subscribed contacts.

Cleaning phase (about three hours). Two problems surface. First, the export includes the 240 cleaned addresses, which must never be imported as active. Second, two tags — vip and VIP-customer — were applied inconsistently by different team members and need merging into one.

Before cleaning, the CSV has 34 columns. After removing Mailchimp internals and standardising dates, it has 16: email, first name, last name, opt-in date, city, loyalty tier, last purchase date, total orders, total spend, preferred category, size, wholesale flag, and four tag columns.

Import phase (about one hour). The 5,255 subscribed contacts import cleanly; the duplicate check flags 12 rows that already existed from a previous partial import. The 810 unsubscribes and 240 cleaned addresses are imported into the suppression list first.

Rebuild phase (about two days). The welcome series takes the longest because the conditional branch on click behaviour has to be recreated. The abandoned-cart flow maps to a trigger on an event plus a wait. The re-engagement flow uses an inactivity trigger.

Verification. Contact count reconciles at 5,255 active plus 1,050 suppressed. Ten spot-checked contacts match their old records on every field. All three automations fire correctly with a test contact. DKIM and SPF both pass.

How to check the migration actually worked

Work through this list before you cancel anything:

• Contact count. Imported + skipped + invalid = exported rows. Every difference has an explanation.
• Suppression. Confirm unsubscribed and cleaned addresses are suppressed in the new platform and cannot be reactivated by a later import.
• Fields and tags. Spot-check ten contacts against their old records, field by field.
• Automations. Trigger each one with a test contact and confirm every step fires in order, including waits and branches.
• Authentication. dkim=pass and spf=pass in the raw headers of a test email to Gmail and Outlook.
• Deliverability. Watch bounce and complaint rates on the first two real sends. Mailerflow automatically suppresses bounces and complaints and monitors reputation, which makes the first sends a good moment to watch those numbers closely.
• Analytics. Confirm opens, clicks and bounces are recorded per campaign in the new platform.

Common mistakes and how to fix them

Importing unsubscribes as active contacts. Fix: import suppression lists before the main audience, or use a platform whose import checks against them.

Losing consent timestamps. Fix: keep the original opt-in date column and map it to a date field. You will want it if anyone asks when a contact consented.

Assuming HTML templates transfer. Fix: rebuild. Exported HTML is usually table-based and breaks in modern editors.

Skipping domain authentication. Fix: add DKIM, SPF and DMARC before the first send, and verify the headers.

Sending a full campaign on day one. Fix: warm up with your most engaged segment first.

Forgetting embedded forms and transactional email. Fix: inventory every place Mailchimp is embedded — website forms, checkout, integrations — and replace each one.

Cancelling too early. Fix: keep Mailchimp until two sends have completed cleanly.

Leaving the old list active. Fix: export a final suppression file before you cancel, in case contacts unsubscribed during the parallel period.

Choosing where to migrate to

Mailchimp is a mature platform with a long track record and a wide integration ecosystem, and its Standard plan trial is free for 14 days (verified 2026-11-09 on mailchimp.com/pricing/marketing). If it works for you, migrating is optional. If you are leaving, the question is which platform fits your list size and sending pattern.

The table below uses only facts verified on 2026-11-09 from each vendor's official pricing page, named in plain text. Plans and limits change, so check the official pages before deciding.

Each of these is designed for a different situation. MailerLite suits senders who want one feature set regardless of tier. Brevo suits teams that want email, SMS and CRM in one place. ActiveCampaign suits teams that lean heavily on automation and CRM. EmailOctopus suits cost-sensitive senders with straightforward needs. Mailerflow suits senders who want unlimited emails on paid plans and AI-assisted building. If you are weighing Mailchimp against a specific alternative in more depth, our comparison of Mailchimp and Mailerflow covers features and pricing side by side, and the broader roundup of Mailchimp alternatives walks through how to choose.

Next steps

A realistic timeline: prep and export in one sitting, import and rebuild over a few days, then two parallel sends before cancelling. If you are on ecommerce flows specifically, the breakdown of Mailchimp vs Klaviyo for ecommerce is worth reading before you rebuild your cart and browse-abandonment automations. Developers moving transactional or API-driven sending should start with the Mailchimp API getting-started guide, and anyone still weighing the cost case should read Mailchimp pricing explained first.

If you want help with the mechanical parts, Mailerflow offers free migration help on eligible paid plans covering contacts, suppression lists, templates and core automations.

FAQ

Can I export my Mailchimp audience for free? Yes. Exporting your audience is available from the Audience section and does not require a paid add-on. Mailchimp emails you a download link when the file is ready, which can take a while for large lists.

Will I lose my unsubscribes? Only if you do not export them. Unsubscribed and cleaned contacts live in separate filtered views, so export each status individually and import them into your new platform's suppression list before importing active contacts.

Do my templates transfer? Not cleanly. Exported HTML is typically table-based and does not paste well into modern block editors, so plan to rebuild. Describing the email to an AI builder can give you a starting design faster than rebuilding from a blank canvas.

How long does a migration take? For a list in the low thousands with a handful of automations, expect a few hours of export and cleaning plus one to three days of rebuilding and verification. Larger lists and complex automations take longer, mostly in the rebuild phase.

Can I keep using Mailchimp while I test the new platform? Yes, and you should. Mailchimp allows cancelling or downgrading at any time (verified 2026-11-09 on mailchimp.com/pricing/marketing), so run one or two sends in parallel before you cut over.

What happens to my sending reputation? Reputation is tied to your domain and IP, not to the platform. Authenticating your domain and warming up with engaged contacts protects it; skipping authentication is what damages it.

Do I need to re-authenticate my domain? Yes. DKIM and SPF records are unique to each platform's account, so you add new records at your DNS provider and verify them before sending.

Ready to move? 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.

Further reading

• Mailchimp Alternatives: How to Choose the Right Platform for Your List