NeverBounce keeps its turnaround answer in a help-centre article at neverbounce.com/help. That page, like the rest of the site, served a captcha and a 403 to every scripted reader on 24 September 2026. So we quote no NeverBounce figure here. The published numbers from vendors whose pages do load give you a fair planning range.
Here's what those vendors state, all read on 24 September 2026. ZeroBounce's docs say "approximately 45-60 minutes per 100,000 contacts". DeBounce says 100,000 emails in less than 2 hours. Emailable claims 250,000 emails in under 7 minutes, and Reoon gives 8 to 12 minutes for 10,000 mixed-quality addresses.
Size isn't the only thing that sets the clock. Every greylisting server forces a wait and a second try, and Microsoft rate-limits verification traffic hard, so a list heavy on Outlook and Microsoft 365 domains runs slower. A deep catch-all pass is a different product with a different clock: Scrubby quotes first results in 24 hours and final results in 72.
You rarely need to watch the progress bar. Upload the file, then do something else until the job finishes. With ZapBounce, a bulk job sends a signed batch.completed webhook the moment it ends, and the batch status endpoint returns live counts for valid, invalid, catch_all and unknown while it runs.
Plan the check a day before the send, not an hour before. That leaves room for a re-check of the unknown rows, which often clear once a greylisting server lets the second probe through. ZapBounce bills nothing for unknown results or duplicates, and 10,000 checks cost $25, so a re-run of the stragglers adds nothing to the bill. The bulk verification speed answer covers the method in more depth.
Related questions
How long does it take to verify 100,000 emails?
Published figures run from about 45 to 60 minutes at ZeroBounce to under 2 hours at DeBounce, both read on 24 September 2026. Emailable states 250,000 emails in under 7 minutes. Lists heavy on Microsoft or greylisting domains take longer at any vendor.
Why is my NeverBounce list stuck on processing?
Large lists and slow receiving servers are the usual cause, because greylisting and rate limits force the verifier to wait and retry. A list with many Outlook or Microsoft 365 addresses is slower still. If a job stalls for hours, contact the vendor with the job ID.
Can I get notified when a bulk verification finishes?
Yes, on ZapBounce a finished bulk job fires a signed batch.completed webhook. You can also poll the batch status endpoint, which returns counts for each of the four results while the job runs.