SendMailOS resources
Move from SendGrid. 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 SendGrid
- Export the relevant Marketing Contacts lists or segments. With the API, create a contact export job, check its status and retrieve each generated CSV file.
- Export suppressions separately: global and group unsubscribes, spam reports, bounced and invalid addresses, plus any other exclusions you maintain.
- Reconcile contacts against every exclusion category before preparing the active CSV. Also inventory your application sends, webhook receiver and template IDs for a separate integration cutover.
SendGrid Marketing Contacts and Suppressions are separate collections. A marketing contact export alone is not an exclusion export. A group-level unsubscribe needs an explicit scope decision before the new audience is built.
2. Map the supported fields
| Source data | Preparation for SendMailOS |
|---|---|
| first_name + last_name | name |
| Selected marketing list labels | tags; choose names intentionally |
| Global/group unsubscribes and other suppressions | Exclude from active CSV; retain reason and original scope |
| Template IDs, custom fields and historical events | Archive or rebuild explicitly; not transferred by this CSV |
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 SendGrid 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: Twilio SendGrid contact exports · Export job status · Suppression categories. 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.