Verify your Substack export before you send

1. Export the CSV from Substack

1. In your Substack dashboard, open the Subscribers page.
2. Apply filters first if you only want part of the list.
3. Use the export option above the subscriber list to export it as a CSV.
4. Download the CSV once the export is ready.

Source: Substack help centre.

2. Upload it to SimpleVerifier

Sign in, upload the CSV as it came out of Substack and every address gets a live mailbox check with catch-all detection. The email column is found automatically.

3. Import the clean file back

You get three files: valid, risky and invalid, each with every column from the original export. Import the valid file back into Substack or your sending tool, and keep risky addresses (usually catch-all domains) out of cold sends.

Common questions

How do I export my subscribers from Substack?

In your Substack dashboard, open the Subscribers page. Apply filters first if you only want part of the list. Use the export option above the subscriber list to export it as a CSV. Download the CSV once the export is ready.

Do I need to change the Substack CSV before uploading it?

No. The email column is found by its header or its contents, so the Substack export works as it is. Every other column is kept, and the cleaned files come back with your original columns so you can import them straight back into Substack.

Why verify a list that came from Substack?

Subscribers who signed up years ago move jobs, abandon inboxes or typed their address wrong. Every send to a dead address in Substack is a bounce on your sender reputation, and many ESPs bill by contact count, so removing dead addresses also lowers the bill.

How much does it cost?

Verification is $29.99 a month with no limit on verifications, for files up to 100,000 rows. See the pricing page for the plans.