Bulk email verification, free for 100 a month
Upload a CSV, TXT or XLSX file and ZapBounce returns every address with a status, a reason code and the server's reply. The first 100 checks each month are free with no card, and unknowns are never billed.
What a B2B list usually looks like coming back
- valid
- 71,40271.4%
- invalid
- 12,88112.9%
- catch-all
- 9,7309.7%
- unknown
- 5,9876.0%
Unknown means the server would not give a straight answer. We report it, and we do not bill it.
The shape a typical list takes, not a measured ZapBounce result. The catch-all share reflects the roughly 28% reported for B2B lists.
How a job runs
Upload the file
CSV, TXT or XLSX, up to 10 MB. For an Excel file we read the first sheet. We read the column that holds addresses, and you match the export back to your own file on the email column.
We deduplicate first
Duplicates inside one upload are collapsed before anything is checked, and you are not charged twice for the same address. Most inherited lists lose several percent here.
Each address is checked
Syntax, then the domain's mail servers, then the SMTP conversation, then a catch-all probe. Greylisted domains get a retry rather than a guess.
Download everything
Download the CSV. Every address comes back with its status, a reason code, the MX host we spoke to and the server's literal reply, so a result you disagree with can be audited rather than argued about.
What you are charged for
| Situation | Billed? |
|---|---|
| Valid or invalid verdict | Yes, one credit |
| Catch-all domain | Yes, one credit, because the finding is real |
| Unknown | No |
| Duplicate within the upload | No |
| Row that isn't shaped like an address | No |
| Job that fails on our side | No, the job is refunded |
Prices run from $5 for 1,000 addresses. Credits never expire.
Reading a cleaned list
Questions about bulk jobs
Is there a free bulk email verifier?
Yes. ZapBounce verifies 100 addresses free every month with no card, in a bulk upload or through the API. Past that, 1,000 checks cost $5, and credits never expire.
What file formats can I upload?
ZapBounce takes CSV, TXT and XLSX uploads of up to 10 MB and exports results as CSV. Match the export to your original file on the email column.
How fast is bulk email verification?
Across the market, 100,000 addresses take from 7 minutes at Emailable to under 2 hours at DeBounce, with ZeroBounce at 45 to 60 minutes (vendor pages, read 24 September 2026). Most of the wait is the receiving mail servers. Greylisted domains take longest, because ZapBounce retries them rather than guessing.
What happens if I run out of credits mid-job?
The job pauses rather than failing. Top up and it resumes from where it stopped, and nothing already verified is charged again.
How long do you keep my list afterwards?
ZapBounce keeps a list until you delete the job, and you can delete it at any time with DELETE /v1/jobs/{id}. The data processing terms at /dpa cover the rest.
Run a sample first
100 free checks a month. Send a few hundred and count what comes back unresolved.