Any verifier holds your list for a while, because it has to run the checks and hand you the results. What matters is how long it keeps them, what it does with them, and whether you can end that early. Your list holds other people's personal data, so these answers belong in writing before you upload.
Retention windows vary a lot. As read on each vendor's own site on 24 September 2026, DeBounce deletes uploads 7 days after upload or validation, and Reoon keeps them 15 days. ZeroBounce, Clearout, emailverify.io and Truelist use 30 days, and Kickbox deletes after 90. Emailable lets you choose between 3 and 30 days.
Put the same questions to NeverBounce: how long a list and its results stay on its servers, whether you can delete them the moment you download, and whether any address is reused or shared. Its help centre and privacy policy on neverbounce.com are where those answers live, so read them in a browser and save a copy with the date.
ZapBounce answers each one on the page. Uploads and results are kept 30 days by default, and each API key has its own window from 0, deleted on download, to 90 days. ZapBounce doesn't sell uploaded addresses, add them to a shared database, contact anyone on your list or reuse a list to improve the product. Data stays in the United States and leaves only for the SMTP probe to the receiving mail server.
The legal side sits in the data processing terms, which form part of the terms of service and list every sub-processor. For the full side-by-side, see ZapBounce vs NeverBounce, or the security page for how the service is run.
Related questions
How long do email verifiers keep uploaded lists?
Between 7 and 90 days at the vendors whose terms could be read on 24 September 2026, and 30 days is the most common window. DeBounce deletes after 7 days and Kickbox after 90.
Does NeverBounce sell my email list?
NeverBounce's own help article and privacy policy on neverbounce.com are the place to confirm that, and it's worth getting the answer in writing. ZapBounce never sells uploaded addresses, never adds them to a shared database and never reuses a list to improve the product.
Where is ZapBounce data hosted?
In the United States. A list leaves that region only for the SMTP probe to the receiving mail server. The sub-processors are Vercel, Amazon Web Services, Cloudflare, Google and Stripe, and changes are announced 30 days ahead.
Can I get a signed data processing agreement from ZapBounce?
Yes. ZapBounce's data processing terms form part of the terms of service, and a countersigned copy is available on request.