SendMailOS resources
Move from Mailchimp. Keep the important details.
Prepare the subscribed audience, preserve the exclusions and rebuild the setup you need. Use this guide alongside your original export records.
1. Export from Mailchimp
- In Mailchimp, open Audience, choose the audience and select Export audience. Download the export when it is ready.
- Unzip the files and keep subscribed, unsubscribed, non-subscribed and cleaned contact types separate. Export every relevant audience; the same address can occur more than once.
- Keep the original marketing-permission fields and opt-in or confirmation timestamps where present. Contact exports do not carry full engagement reporting; archive reports separately.
A subscribed entry in one audience does not override an unsubscribe or exclusion elsewhere. Decide the intended scope using your original permission records before preparing the new audience.
2. Map the supported fields
| Source data | Preparation for SendMailOS |
|---|---|
| Email Address | |
| First Name + Last Name | name |
| TAGS or selected group/list membership | tags; separate values with semicolons |
| Unsubscribed, cleaned, non-subscribed files | Exclude from active CSV; retain the original records |
| Opt-in/confirmation and marketing permissions | Preserve in your archive; not mapped by this three-column import |
The standard dashboard import expects email, name and tags. It does not translate provider status fields or rebuild old automations. Keep the original export before editing.
3. Check the file, then run a controlled pilot
Use a subscribed-only file with all exclusions removed. Test with a small batch you can inspect: verify names, tags, duplicate handling and counts. Confirm previously excluded addresses remain excluded from the intended audience. Review enrollment behavior before enabling any workflow.
4. Move the sending setup
Add your sending domain and publish the exact records shown by SendMailOS. Recreate templates and workflows, configure the new application credentials, then test against mailboxes you control. Check the accepted, delivered, bounced and unsubscribed outcomes before increasing traffic.
Keep the old platform and its records until the cutover is reconciled. Disable duplicate scheduled sends, old form connections and old application credentials at the appropriate point in your own cutover checklist.
What this guide does not transfer
This is a manual export, preparation and rebuild guide. It does not connect to your Mailchimp account, move reports, preserve provider message IDs, import consent history into custom fields, or translate workflow logic automatically. Complete the pilot before moving your full audience.
Export references checked 24 October 2026: Mailchimp contact export guide · Mailchimp account export. Provider screens and export fields can change; follow the linked current instructions.
Questions and answers
Frequently asked questions
Will my old automations and reports move automatically?
No. This is a manual migration. Rebuild and test workflows, templates, forms and integration settings in SendMailOS. Keep your original reports and export history separately.
Should I import unsubscribed or bounced people as active subscribers?
No. Keep unsubscribed, complained, invalid and other excluded addresses out of the active import. Preserve the original exclusions and consent records. The standard dashboard CSV import uses email, name and tags; a provider status column does not transfer those statuses.
Can I use my own server after switching?
Yes. Unlimited emails with your own server are available from €12/month. This means no monthly platform email quota for messages actually sent through your connected server. VPS costs, warm-up, fair use, server capacity, subscriber limits and other plan limits still apply.
Choose your next step
Prepare your audience, connect your application, or create an editable email design.