Cognism claims Diamond Data accuracy but email servers still reject addresses. BounceZero adds a real-time SMTP layer on top of your Cognism exports - so no bounce ever surprises you.
100 free verifications/month - No credit card required
Cognism’s Diamond Data is phone-verified - a human confirmed the person exists. But phone verification says nothing about whether their mail server will accept your email today.
Cognism verifies people by phone, not mailboxes by SMTP. A contact can be 100% real while their email address was deprovisioned last quarter - the server rejects it either way.
People change jobs constantly. An email that was valid when Cognism sourced it may point to a dead mailbox by the time you export it. Verification at send-time is the only guarantee.
23% of B2B domains accept mail for any address, so basic checks mark everything "valid". BounceZero's 3-probe catch-all analysis tells you which of those addresses actually exist.
Every email in your Cognism export runs through our full verification pipeline - results in seconds, up to 99.8% accuracy in internal testing on SMTP-verifiable addresses against the industry benchmark of ~95%.
Live SMTP handshake confirms the exact mailbox exists on the recipient server - the check Cognism's phone verification can't perform.
Triple-probe analysis distinguishes genuinely deliverable addresses from catch-all domains that silently accept everything.
Flags info@, sales@ and admin@ addresses that hurt engagement rates and trigger spam filters in cold outreach.
Catches temporary and throwaway domains that occasionally slip into B2B databases through form fills.
Confirms the domain still has live mail servers - companies get acquired, rebrand, and shut down mail infrastructure.
Identifies recycled addresses converted into spam traps - the single fastest way to destroy your sender reputation.
No integration setup, no API keys required to start. Export, verify, re-import - a 10K-contact list is done in 5-10 minutes.
Build your list in Cognism Prospector or Sales Companion and export it as CSV. Include the email column - every other field is preserved untouched.
Drag and drop your Cognism CSV into the BounceZero dashboard. We auto-detect the email column and support dashboard jobs up to 1,000,000 addresses.
All 6 checks run on every contact: SMTP mailbox probe, 3-probe catch-all analysis, role, disposable, MX and spam trap screening. 10K emails take 5-10 minutes.
Get your list back split into Deliverable, Risky and Undeliverable - with per-address confidence scores and full check details for every Cognism contact.
Push verified contacts back into Cognism, Salesforce, HubSpot or your outreach tool. Send only to Deliverable and keep your bounce rate under 0.5%.
You already pay a premium for Cognism data. Protecting that investment costs $3 per 1,000 emails - a rounding error next to a burned sender domain.
New to verification? Start with the complete email verification guide.
Everything Cognism users ask before verifying their first export.
BounceZero works with every Cognism export via CSV - export from Prospector or Sales Companion, upload to BounceZero, and download segmented results in minutes. For automated pipelines, our REST API (provider-dependent response time) verifies Cognism contacts in real time as they enter your CRM or outreach tool. No native plugin is required.
Cognism's Diamond Data is phone-verified: a human confirmed the person and role exist. That's excellent for accuracy of identity, but it doesn't test whether the mail server accepts email for that address today. B2B emails decay at roughly 22% per year as people change jobs, so BounceZero adds a live SMTP layer that checks deliverability at the moment you actually send.
Around 23% of B2B domains are catch-all - they accept mail for any address, so simple verifiers mark everything valid. BounceZero runs a 3-probe catch-all analysis that identifies which addresses on those domains genuinely exist, so catch-all contacts get a real confidence score instead of a blanket "valid".
A typical 10K-contact Cognism export finishes in 5-10 minutes. Bulk uploads support up to 1,000,000 addresses per dashboard job, and single-email API verifications return with timing that varies by provider and verification path on average - fast enough to verify contacts inline during enrichment.
No. Cognism is known for GDPR-compliant sourcing, and BounceZero maintains that posture: we're a UK company, we process your list solely to return verification results, and we never resell, enrich or reuse your contact data. Verification actually supports compliance by ensuring you only email working, current addresses.
Pricing is $3 per 1,000 verifications - a 10K Cognism export costs $30 to fully verify with all 6 checks. Every account also includes 100 free verifications per month with no credit card required, so you can test on a real segment before paying anything.
Verify your first 100 Cognism emails free - up to 99.8% accuracy in internal testing on SMTP-verifiable addresses, results in seconds, no credit card required.
Start Verifying FreeUp to 99.8% accuracy in internal testing on SMTP-verifiable addresses. $3 per 1,000 verifications. Results in seconds.
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