Free bulk email verifier

What this tool does

The free bulk verifier takes a pasted list of addresses, removes duplicates, and runs each one through the same engine as the single-address checker: syntax, DNS and MX, reputation lists, a real SMTP handshake and a catch-all probe. Addresses are verified one after the other rather than all at once so that no mail server sees a burst from a single source, which keeps the results honest and the engine welcome. A progress bar and four counters fill in as the job runs, and each row shows its verdict, score, reason and mailbox provider.

When it finishes you can copy everything as CSV with a header row, ready to paste into a spreadsheet or your newsletter platform's import. The columns are email, status, score, reason, provider and flags (disposable, role, free, catch-all), which is the same layout the full product exports.

Limits, and why they exist

Anonymous checks are limited to 20 per hour per network. That is deliberate: SMTP verification touches other people's mail servers, and an open, unlimited tool would be used to validate stolen lists. The counter under the box shows what is left this hour. A free account lifts the limit, adds 100 credits that never expire, and unlocks the real bulk cleaner: upload a CSV, XLSX or TXT of up to 500,000 rows, or import an audience straight from Mailchimp, Klaviyo, Brevo, HubSpot and other platforms. Duplicates and malformed rows are removed free before anything is charged, hundreds of checks run in parallel with polite per-domain limits, and you download deliverable, risky and undeliverable segments with your original columns preserved.

What to do with the results

Send to the deliverable rows. Suppress the undeliverable rows (they will bounce and damage your sender reputation; around 2% bounce rate is where Gmail and Yahoo begin to throttle). Treat risky rows with care: catch-all addresses often work but cannot be confirmed, role accounts such as info@ are shared inboxes with low engagement, and greylisted addresses can be re-checked later. Unknown rows are usually temporary and resolve on a second pass.