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Guide · 5 minute read

Moving your list from Mailchimp

Export your audience, bring it over in one CSV, and keep your unsubscribes honored. The move takes about 15 minutes.

If you send a newsletter now and then, a monthly plan sized to your whole list is mostly paying for months you don't send. Moving to pay-per-send is a CSV and a DNS record away. Here's the whole trip.

1. Export your audience

In Mailchimp, open your audience's contacts and use its export option. You'll get a download containing CSV files: subscribed contacts, unsubscribed contacts, and cleaned (bounced) addresses. Keep all of them.

2. Import only the people who are still subscribed

On Flatstamp, open Contacts and upload the subscribed file. We read the email, first name and last name columns, skip addresses that can't receive mail, and flag role addresses (like info@) and throwaway domains so you can decide on them.

Don't import the unsubscribed or cleaned files as subscribers. Those people asked to stop, or their mailbox no longer exists; mailing them hurts your reputation everywhere.

3. Set up your sending domain

Add your domain on the Sending domains page. We show a few DNS records (DKIM, a bounce address, SPF and DMARC) to add where your domain is hosted, then check them for you every hour. If you already had DKIM set up for Mailchimp, keep it; each service signs with its own record.

Check your domain's email setup now (free) →

4. Add your postal address and buy stamps

Every marketing email must carry a postal address; add yours once on your account page and we put it in every footer, with a one-click unsubscribe. Then buy a book of stamps: one stamp per email per person, and they never expire.

5. Rebuild your template and send a test

Pick one of our templates and paste your content in. Send yourself a test (one stamp), check it on your phone, then schedule.

What it costs

A 2,500-person list mailed once a month is 30,000 emails a year: two Starter books, $40 a year. Put your own numbers in the calculator to compare with what you pay now.

Compare a year of your email →

Updated October 23, 2026