How big a list can I upload?

You can upload lists of any size within your plan's credits. Large lists run as background jobs, so you can close the page and come back or wait for the webhook.

What format does the file need?

A CSV with one email address per row. A header row is fine. The results file keeps your original columns and adds the verification fields.

Will I be charged for unknown results?

No. Unknown means the mail server did not answer, so we do not bill for it. You can resubmit those addresses later.

Can I automate list cleaning?

Yes. Use the bulk API directly, or connect VeriDock through Zapier, Make or n8n to verify new contacts as they arrive.

Free tool

Bulk email verifier

Upload your list, and VeriDock checks every address against its mail server. You get back a clean file with a status and reason for each row, ready to import into your email tool.

Upload a CSV from your dashboard

Start with 250 free checks

How bulk verification works

Upload a CSV with one email per row, or send an array to the bulk API endpoint. We check each address with the same live checks used for single lookups, then return a results file you can download or stream line by line as NDJSON.

Upload a CSV from the dashboard or send it through the API.
Each row is checked for syntax, domain, MX, SMTP, catch-all and disposable status.
Download results with a status, reason and score for every address.
Subscribe to a signed webhook that is retried for 24 hours when the job finishes.

What to do with the results

Remove undeliverable addresses completely. They will bounce and hurt your sender reputation. Treat risky addresses as optional: keep the ones from real customers, and drop disposable and role-based ones if you care about engagement. Unknown results are free, so retry them later.

Pricing for large lists

The free tier covers 250 checks every month. Paid plans start at $9 a month for 5,000 checks, which works out to $1.80 per 1,000, and the cost per 1,000 falls as you move up. Credits roll over for 60 days on paid plans and unknown results are never billed.

When to clean your list

Clean a list before a large send, after importing contacts from an event or purchase, and on any list older than six months. Email addresses decay, since people change jobs and companies close domains, so a list that was clean last year will have new bad addresses today.

Frequently asked questions

Start with 250 free checks Read the API docs

How bulk verification works

Upload a CSV from the dashboard or send it through the API.

Each row is checked for syntax, domain, MX, SMTP, catch-all and disposable status.

Download results with a status, reason and score for every address.

Subscribe to a signed webhook that is retried for 24 hours when the job finishes.