Checklist

Email Platform Migration Checklist: 12 Steps for Zero Subscriber Loss

Moving email platforms is nerve-wracking. Your subscriber list is your most valuable marketing asset. This 12-step checklist ensures zero subscriber loss, no deliverability tanking, and a clean transition between Mailchimp, Kit, beehiiv, ActiveCampaign, or Brevo.

15 min readUpdated March 2026

Why Migrate? The Cost Math

Mailchimp Standard at 5,000 contacts costs $75/month ($900/year). beehiiv Scale at unlimited subscribers costs $49/month ($588/year). Kit Creator at 1,000 subscribers costs $39/month ($468/year). Brevo Standard at 5,000 emails/month is $18/month ($216/year). The savings justify the migration effort for most teams.

The 12-Step Migration Checklist

1.

Export your complete subscriber list.

Mailchimp: Audience > All contacts > Export Audience (CSV). Includes tags, merge fields, subscription status. Kit: Subscribers > Export CSV. Includes tags and custom fields. Substack: Settings > Exports > Export email list.

2.

Clean your list before importing.

Remove bounced emails, unsubscribes, and spam complaints. Mailchimp infamously counts unsubscribed contacts toward your bill. beehiiv and Kit do not — but importing dirty data to any platform hurts deliverability from day one.

3.

Set up your new platform account and pick your plan.

beehiiv Launch: free for 2,500 subscribers. Kit Newsletter: free for 10,000 subscribers. Brevo Free: 300 emails/day, unlimited contacts. ActiveCampaign Starter: $15/month for 1,000 contacts. Start on the free tier if possible and upgrade later.

4.

Connect and verify your custom domain.

Add SPF, DKIM, and DMARC records for your sending domain. Every platform requires this for optimal deliverability. Allow 24–48 hours for DNS propagation. Do not send any emails until domain verification is complete.

5.

Import subscribers to the new platform.

Upload your cleaned CSV. Map fields carefully: first name, last name, email, tags, and custom fields. beehiiv and Kit both support tag imports. ActiveCampaign supports list-based import with automation triggers.

6.

Verify subscriber count matches.

Compare imported count to your export count minus cleaned records. Any discrepancy means records were rejected (usually duplicate emails or invalid formats). Check import logs for errors.

7.

Rebuild your automation sequences.

Welcome sequences, nurture flows, and drip campaigns don't transfer between platforms. Screenshot your existing automations in Mailchimp or Kit before cancelling. Rebuild the highest-revenue ones first on the new platform.

8.

Warm up your new sending domain.

Do not blast your entire list on day one. Send to your most engaged subscribers first (50–100 openers), then gradually increase volume over 2 weeks. Most deliverability issues come from skipping warmup. beehiiv and Kit handle warmup automatically for small lists.

9.

Update all signup forms, landing pages, and embedded forms.

Every form on your website, in your footer, on your landing pages, and in popups needs to point to the new platform. Mailchimp embed codes won't work with beehiiv. Replace them all before going live.

10.

Send a test email to yourself and 2–3 team members.

Check: subject line, preview text, from name, reply-to address, links, images, unsubscribe link. Test on Gmail, Outlook, and Apple Mail. Check spam folders. Do not skip this step.

11.

Send your first real email from the new platform.

Start with your most engaged segment (subscribers who opened in the last 30 days). Monitor open rates and bounce rates closely. If open rates drop below 15% or bounce rates exceed 3%, pause and investigate.

12.

Cancel the old platform after 2 weeks of stable sends.

Keep the old platform active for 2 weeks as a safety net. If deliverability tanks on the new platform, you can fall back. After 2 stable weeks, cancel and save. Download a final full export from the old platform before cancelling.

Platform-Specific Notes

PlatformPrice (Paid Entry)Export QualityKey Gotcha
MailchimpEssentials $13/moGood CSV exportCounts unsubscribes toward billing
KitCreator $39/moGood CSV with tagsFree tier walls off automations
beehiivScale $49/moCSV export availableNo visual automation builder
ActiveCampaignStarter $15/moGood CSV exportNo free tier at all
BrevoStarter $9/moCSV exportFree tier limited to 300 emails/day

Frequently Asked Questions

Will I lose subscribers during migration?

Not if you follow the checklist. The #1 cause of subscriber loss is importing a dirty list (bounced/invalid emails) that triggers the new platform's spam protection. Clean your list in Step 2 and you'll import 100% of valid subscribers.

How long does email migration take?

The actual migration takes 2–4 hours. Domain warmup takes 1–2 weeks. Total timeline from start to old-platform cancellation: 2–3 weeks.

Can I migrate Mailchimp automations to beehiiv?

No. Automations never transfer between platforms. beehiiv Scale ($49/month) has basic automation sequences, but not the visual builder Mailchimp or Kit offer. Screenshot and rebuild manually.

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