Switching to Mailchimp isn’t just about changing platforms. It’s about migrating your contacts responsibly, resetting your email practices, and setting yourself up for stronger deliverability. These 7 steps (plus one expert tip) walk you through what to do before, during, and after migration to help ensure a smooth transition.
Before you migrate
Before you import contacts or send a single email campaign, it’s important to confirm that your audience is permission-based, clean up your data, and authenticate your domain. These steps help improve inbox placement and keep your future sends from getting flagged as spam.
1. Ensure contacts have opted in
Why: Sending to people who didn’t explicitly ask for your emails could put your deliverability and reputation at risk.
How:
- Use Mailchimp signup forms with reCAPTCHA and double opt-in.
- For offline or older contacts, send a re-confirmation email through your old email service provider (ESP) directing them to a Mailchimp signup form.
Why we verify imported contacts
2. Import suppression lists
Why: Avoid accidentally emailing unsubscribed or bounced contacts by importing them as a suppression list.
How:
- Export unsubscribed and bounced contacts from your previous ESP.
- Import them into Mailchimp as non-subscribed by following these instructions.
Note: You'll need to create a suppression list for each of your audiences in Mailchimp (if you have more than one).
3. Authenticate your domain
Why: Authenticating your domain helps email providers recognize you as a legitimate sender and improves inbox placement.
How:
- Set up SPF and DKIM records to verify your domain and sender identity.
How to authenticate your domain
During migration
You’ve prepped your data, confirmed permission, and verified your domain. Now you’re ready to move into Mailchimp.
4. Import contacts as a single audience
Why: Brings your cleaned, structured audience into your new Mailchimp setup. Maintaining one audience helps Mailchimp manage your list health, bounces, and unsubscribes effectively.
How:
- Use Mailchimp’s import tools and map fields correctly (name, email, signup source).
- Import to a single audience and use tags, custom fields, or segments instead of creating multiple audiences.
Also important: Recreate automations (like welcome series or abandoned cart flows) and signup forms that were active in your previous ESP.
5. Archive inactive contacts
Why: Pruning your list reduces bounce rates and improves engagement metrics.
How:
- Archive contacts who haven’t opened recent campaigns (last 5+ emails or within the past 90 days).
6. Set up 2-factor authentication
Why: Securing your account protects both your data and your sender reputation.
How:
- In Mailchimp, go to Account → Settings → Security and enable 2FA via SMS or an authenticator app.
7. Insert an unsubscribe link
Why: It’s required by law and signals to inbox providers that you’re a responsible sender. Mailchimp requires an unsubscribe link for marketing emails.
How:
- Use Mailchimp’s *|UNSUB|* merge tag in your email templates or Campaign Builder.
Warm-up reminder: Avoid sending to your entire list right away. Start with your most engaged contacts, then gradually increase sending volume over your next few sends. This builds trust with email providers and protects your sender reputation.
After you launch
Once you’ve sent your first email campaign from Mailchimp, whether to a small test segment or an engaged portion of your audience, you’ve officially launched. What you do next is just as important as what you did before.
Expert tip: Re-engage stale contacts
While you still have access to your old ESP, use it to send a re-introduction email reminding contacts of your brand and asking them to opt in again via your Mailchimp signup form. Contacts who re-subscribe through the form will become part of your active Mailchimp audience.
Keep deliverability on track
A strategic start makes it easier to get the most out of Mailchimp. Keep these tips in mind:
- Start small: Send to your most engaged contacts first and scale up gradually.
- Send consistently: Weekly sending helps maintain domain reputation.
- Set team expectations: Performance may dip slightly during the warm-up period. Align on what success looks like in the first 30-60 days.
- Monitor performance: Watch opens, clicks, bounces, and unsubscribes closely in the first 30 days.
- Refine as needed: Adjust subject lines, segmentation, and content based on engagement trends.
Migrating to Mailchimp is more than a platform switch—it’s a fresh start for your email strategy. With the right setup and sending habits, you’ll establish credibility with inbox providers and connect with your audience from the start.
Looking for more resources?
- Watch our onboarding videos
- Read a Comprehensive email authentication guide
- Discover more about email domain authentication