We ran 50,000 ZoomInfo-sourced contacts through BounceZero to get real-world accuracy numbers. Here is what we found - and the one step ZoomInfo teams always skip.
50,000 ZoomInfo contacts sourced Jan-Jun 2026, verified via BounceZero immediately after export.
ZoomInfo maintains one of the largest B2B databases in existence - 260M+ contacts across 100M+ companies. The database is built through a combination of web crawling, user-contributed data, and third-party partnerships. The accuracy gap exists because email addresses change faster than any data provider can refresh them.
B2B email addresses become invalid at approximately 22% per year. A 60-day refresh cycle still means 3-4% of the database is stale at any given moment.
13.6% of ZoomInfo contacts are on catch-all domains - servers that accept any email address. Standard SMTP verification marks these as valid; only probe-based verification can identify the catch-all pattern.
ZoomInfo org chart data (title, department, manager) is refreshed on a different cycle than email data. Contacts with current titles may have departed from the listed email domain.
| Metric | ZoomInfo | Apollo.io | After BounceZero |
|---|---|---|---|
| Valid email % | 78% | 73% | 99%+ |
| Catch-all % | 14% | 18% | Flagged/removed |
| Invalid % | 6% | 6% | Removed |
| Bounce rate (unverified) | 14-22% | 20-27% | < 1% |
| Monthly cost | $1,000-5,000+ | $49-99 | |
| Verification needed | Yes | Yes | ✓ Done |
Key takeaway: verification closes the gap entirely. Apollo verified with BounceZero ($3/1K) achieves the same inbox delivery as ZoomInfo - at 95% lower total cost for the data layer.
CSV export with email column. Target your ICP precisely - ZoomInfo filters are strong enough to export exactly who you need.
Upload CSV. Remove 22% invalid/catch-all/disposable contacts. Download clean list. Takes 8 minutes per 10K contacts, $3/1,000.
Import verified CSV to your sending platform. Expected bounce rate: under 1%. Domain reputation protected.
Apollo, ZoomInfo, Lusha and Cognism all have accuracy gaps - verify exports before sending
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