Bulk / list verification

Bulk verification cleans an entire list in one job — by uploading a file in the dashboard, or by submitting addresses through the Bulk jobs API.

Upload a file

1. Open Bulk verification and upload a CSV or XLSX file.
2. Map the column that contains the email addresses.
3. Start the job. Large lists process in the background — you can leave the page.
4. When it finishes, download the results file.

File tips

• One address per row, with a header row.
• De-duplicate first to avoid spending credits twice on the same address.
• Very large lists are processed in batches; progress is shown live.

Read the results

The results file adds the verification columns to each row — status, sub-status, score, and flags. A typical workflow is to keep deliverable, drop undeliverable, and review risky / accept-all before sending.

See Understanding results for what each column means.

Verify a list via API

If you’d rather not upload files, submit and poll jobs programmatically:

• Create a job and add addresses → Bulk jobs API
• Authenticate your requests → Authentication

After verifying

• Suppress undeliverables in your ESP so they’re never emailed again.
• Re-verify older lists periodically — addresses decay over time.
• Consider the real-time widget to keep new sign-ups clean at the source.