Transparency about our data sources and verification methodology is important to us. Here is how Cleanlist obtains and verifies contact information.
Data sourcing
Cleanlist does not maintain a static database of contacts. Instead, we use a 15-step real-time waterfall - querying multiple vetted third-party data providers in sequence for each lookup. This ensures data freshness since results are sourced at the time of your request, not from a stale database.
Email providers
We cascade through 15+ specialized data providers including Hunter.io, FindyMail, LeadMagic, Datagma, IcyPeas, Prospeo, AnyMailFinder and many others. Each provider uses different data sources and methodologies, which is why the waterfall approach delivers significantly higher match rates than any single provider.
Phone providers
Phone data is sourced through providers like Wiza, ProxyCurl and others, which specialize in professional contact data from publicly available sources.
Verification methodology
Every email found goes through independent verification via services like ZeroBounce and Emailable before being delivered to you:
Format verification - RFC 5322 compliance check
Domain validation - Confirms the email domain exists and has valid MX records
SMTP verification - Checks deliverability without sending an email
Disposable email detection - Flags temporary or throwaway addresses
Catch-all detection - Identifies domains that accept all email addresses
Deliverability scoring - Rates each email as reliable, risky, or unknown
Phone numbers are verified with format standardization (E.164) and carrier identification.
Data accuracy
Because Cleanlist uses real-time lookups rather than a static database, our data is as fresh as the underlying providers. Match rates vary by region and industry, but the waterfall approach typically delivers 2-3x higher match rates than any single provider.
Reporting inaccurate data
If you receive data you believe is inaccurate, contact us at [email protected] and we will investigate.