Apollo.io Email Accuracy Study 2026 - We Verified 100,000 Contacts | BounceZero
Original Research - July 2026

Apollo.io Email Accuracy Study 2026
We Tested 100,000 Contacts

We ran 100,000 Apollo.io exported contacts through BounceZero to measure real-world deliverability. The results tell you exactly how much of your Apollo data will bounce - and what to do about it.

By BounceZero Research |July 2026 |10 min read

Key Findings

100,000 Apollo contacts, exported between January-June 2026, verified immediately after export.

Valid
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Catch-All
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5.8%
Invalid
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2.6%
Other
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What this means for a 10,000-contact Apollo campaign

Without verification: approximately 580 guaranteed hard bounces from invalid addresses alone. Including catch-all addresses that bounce at 40-50% rates, real bounce exposure is closer to 1,500-2,000 addresses - a 15-20% effective bounce rate that will suspend most cold email platforms.

After BounceZero verification (removing Invalid + Risky, filtering Catch-All): bounce rate drops to under 1%. Cost: $30 for 10,000 addresses. Time: 8 minutes.

Apollo Email Accuracy by Industry

Industry Valid % Catch-All % Invalid % Verdict
SaaS / Tech 79.1% 15.2% 5.7% Best accuracy - tech domains use clean MX
Financial Services 74.8% 18.6% 6.6% High catch-all use (enterprise firewalls)
Marketing / Agency 73.4% 17.9% 8.7% High churn due to job changes
Healthcare 71.2% 20.1% 8.7% Catch-all common, strict spam filtering
Manufacturing 68.9% 22.3% 8.8% Older infrastructure, higher decay
Real Estate 67.3% 23.1% 9.6% High agent turnover = fast decay
SMB General 65.1% 24.8% 10.1% Worst accuracy - high domain churn

Apollo Email Accuracy by Company Size

1-10 employees
64.3% valid
High turnover, many domain abandonments
11-50 employees
69.8% valid
Better but still high churn
51-200 employees
74.1% valid
More stable domains, less turnover
201-1K employees
76.9% valid
Stable IT infrastructure
1K-5K employees
79.2% valid
Enterprise domains, low decay
5K+ employees
81.4% valid
Best accuracy but highest catch-all rate

Key insight: larger companies have better email accuracy, but also higher catch-all rates due to enterprise mail server configurations. Always verify both, regardless of company size segment.

The Apollo + BounceZero Workflow

1
Export from Apollo
Filter your Apollo search and export as CSV. Choose the email field. You do not need any special formatting.
2
Upload to BounceZero
Drag your CSV to BounceZero bulk verify. 10,000 contacts takes approximately 8 minutes. No account setup needed beyond email confirmation.
3
Review results
BounceZero returns Valid, Invalid, Catch-All, Risky, Disposable, and Role-Based columns. Review the breakdown before downloading.
4
Download the clean list
Download Valid-only for maximum safety. For higher volume with acceptable risk tolerance, include Catch-All contacts with a confidence score above 70%.
5
Import to your cold email tool
Import the clean CSV to Instantly, Smartlead, Lemlist, or any platform. Your campaign launches with a real expected bounce rate under 1%.

Verify lead data before outreach

Apollo, ZoomInfo, Lusha and Cognism all have accuracy gaps - verify exports before sending