An 8-stage email waterfall that crawls websites, GitHub, Twitter, Hunter.io, Apollo.io, and Clearbit — then generates patterns and SMTP-verifies until it finds a deliverable address or confirms none exists.
113| 113| 113| 72| 114| 114| 114| 73|The contact waterfall runs up to 8 enrichment stages in sequence — website crawl, GitHub, Twitter, Hunter.io, pattern guess, Apollo.io, Clearbit, SMTP verification — stopping the moment it finds a deliverable address. Each stage feeds the next, building a complete contact profile from multiple sources.
119| 119| 119| 78|Uses utils/contact_waterfall.py
Jessica drops a company name or LinkedIn URL into the waterfall. While it runs in the background, she works other leads. The system comes back with verified emails ready to put in a sequence — no manual multi-tool hopping.
147| 147| 147| 106|Tom's team was hitting 15% bounce rates on imported lists. Every email now passes SMTP verification against the recipient mail server before it reaches a sequence. Invalid addresses are caught before they damage sender reputation.
152| 152| 152| 111|Riya runs a batch of 20 target accounts through the waterfall before building a campaign. She knows exactly how many reachable contacts exist in her ICP before committing spend on creative and sequencing.
157| 157| 157| 116|Hunter.io finds emails from one source — its own database. PQ Intel runs 8 stages with a fallback cascade. If Hunter.io returns nothing, the waterfall tries pattern generation, then Apollo.io, then Clearbit, then SMTP verification. Each stage is an independent channel, not a single-source dependency.
169| 169| 169| 128| 170| 170| 170| 129|8-stage waterfall — website, GitHub, Twitter, Hunter.io, pattern, Apollo.io, Clearbit, SMTP verify. Falls back across stages until found or exhausted.
175| 175| 175| 134|Single-source lookup against Hunter's own email database. No fallback, no pattern generation, no SMTP verification from other sources.
179| 179| 179| 138|Per-contact results including enrichment data from every stage, so you know exactly what was found and where.
190| 190| 190| 149|You have 50 target accounts and need verified contacts for each. Run the entire list through the waterfall in batch mode. Every contact that returns a verified email is ready for sequencing — those that don't are flagged so you know where your coverage gaps are.
You bought or downloaded a prospect list from an event or data broker. Before wasting budget on sequences, run it through SMTP verification. Contacts that bounce are removed automatically — your sender reputation stays clean and your metrics reflect real engagement.
You're testing a new market segment and want to know if enough reachable contacts exist before building campaigns. Run 10-20 representative accounts through the waterfall. The hit rate tells you whether the segment is viable or needs refinement.
This feature works best alongside:
Discover contactable leads from signals across 13+ platforms.
Define your target per tenant and score contacts automatically.
Track discovered contacts through the deal pipeline.
Discover decision-makers at target accounts, then enrich via the waterfall.
Send verified contacts through automated email and LinkedIn sequences.
Score enriched contacts by ICP fit before sending outreach.
Up to 8: website crawl, GitHub, Twitter/X, Hunter.io, pattern generation, Apollo.io, Clearbit, SMTP verification.
212| 212|Connects to the recipient mail server via MX lookup without sending mail.
219| 219|Reports the deepest stage reached transparently.
226| 226|Hunter.io is single-source. PQ Intel cascades across 8 independent sources.
240| 240|Yes. Batch mode accepts CSV uploads of names, companies, and domains. The waterfall processes each contact in sequence, returning a results file with per-contact status, source attribution, and verified email or failure reason.
Most contacts resolve in under 30 seconds. The waterfall stops at the first verified email, so common patterns return quickly. Uncommon domains may take longer as the system progresses through all 8 stages.
Per-contact results include verified email, source attribution (which stage found it), phone numbers where available, company enrichment data including role and domain, and composite ICP score. You get a full contact profile, not just an address.
Yes. Contacts can be re-run at any time. This is useful when a contact changes jobs or company — the waterfall re-discovers their new email from the updated domain. Results are timestamped for audit trail.
The waterfall reports the deepest stage reached and a clear failure reason — no website found, no matching pattern, or SMTP reject. This helps you decide whether to source the contact manually or skip them.
8 stages, one click, deliverable results. Start with a free trial.
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