Collecting leads is only the first step — qualifying them quickly and accurately is where revenue teams win. In this guide you’ll learn how to build a reliable, automated lead qualification workflow using a web form, Hunter for email verification, MadKudu for lead scoring, and n8n to orchestrate the process and notify your team in Slack.
Why automate lead qualification?
Manual lead triage slows down sales, wastes SDR time, and causes missed opportunities. An automated lead qualification pipeline ensures only valid, high-potential leads are routed to sales while low-fit or invalid leads are handled gracefully. Using tools like MadKudu (for fit scoring) and Hunter (for email verification) inside n8n gives you a flexible, maintainable, and transparent workflow.
Overview of the workflow
This workflow follows a simple, effective sequence:
- Form Trigger: Capture lead details from a web form or embedded form (Typeform, Google Forms, custom HTML form).
- Hunter Verification: Verify the email validity and status.
- Email Valid Check: Route valid addresses to scoring; route invalid addresses to an invalid email handler.
- MadKudu Scoring: Enrich and score leads with MadKudu to compute customer fit and likelihood to convert.
- Fit Score Check: Compare the MadKudu fit score against a threshold (example: 60).
- Slack Notification (or Sales Routing): Notify the appropriate channel for high-fit leads; handle low-fit leads differently.
Step-by-step setup (n8n workflow)
1. Add credentials
Before building the flow, add credentials for:
- MadKudu API (HTTP header auth)
- Hunter API (email verifier)
- Slack (Bot token)
Store these in n8n’s credentials manager so nodes can reference them securely.
2. Form Trigger
Use n8n’s Form Trigger or any webhook-enabled form. Collect at minimum:
- Business email
- First and last name (optional but helpful)
- Company domain (if available)
When testing, use the built-in test mode to submit a sample email and ensure the workflow receives the payload.
3. Hunter — Email Verification
Connect the Hunter Verification node and pass the submitted business email. Hunter returns validation results (e.g., status: valid/invalid/accept_all/disposable). Use an IF node (Email Valid Check) to split based on the status value. Route invalid addresses to an Invalid Email Handler (a no-op or automated follow-up email) and valid addresses to MadKudu.
4. MadKudu — Lead Scoring
Call MadKudu’s persons endpoint with the verified email to retrieve enrichment and scoring (customer_fit.score and top signals). Use this response inside a Fit Score Check IF node to compare the numeric fit score against your threshold, for example:
- High-fit: score > 60 -> notify sales via Slack
- Low-fit: score <= 60 -> send to Low Fit Handler (nurture list or CRM entry)
Slack notification & message formatting
For high-fit leads, create a Slack Notification node that publishes to a designated sales channel. Format your message to provide essential context so SDRs can act immediately. Example template from the workflow:
⭐ Got a hot lead for you {{ $json.properties.first_name }} {{ $json.properties.last_name }} from {{ $json.company.properties.name }} ({{ $json.company.properties.domain }}) based out of {{ $json.company.properties.location.state }}, {{ $json.company.properties.location.country }}.
{{ $('MadKudu Scoring').item.json.properties.customer_fit.top_signals_formatted }}This includes the candidate’s name, company, domain, location, and the top-fit signals returned from MadKudu so reps know why this lead is prioritized.
Handling low-fit and invalid leads
Not every lead is immediate-sales ready — that’s OK. Use dedicated handlers:
- Invalid Email Handler: Log invalid submissions, optionally trigger an automated verification email, or notify marketing to review suspicious leads.
- Low Fit Handler: Add to a nurture sequence, tag in CRM, or route to marketing automation for qualification over time.
Tuning fit thresholds and signals
MadKudu provides both a numeric customer fit score and qualitative signals. Choose a threshold based on your historical conversion data. A common starting point is 60, but you should:
- Run A/B tests with different thresholds
- Monitor conversion rates for leads routed to sales
- Adjust the threshold and signal filters as your business evolves
Best practices and tips
- Test the end-to-end workflow in n8n’s test mode before activating in production.
- Log every decision point (verification, score, routing) to maintain auditability and enable troubleshooting.
- Keep Slack notifications concise — include a direct link to CRM or the lead record if possible.
- Use rate limits and error handling around external API calls (Hunter & MadKudu) to avoid workflow failures.
- Consider enrichment fallbacks (e.g., Clearbit) if MadKudu or Hunter response is incomplete.
Troubleshooting checklist
- No Slack message: verify Slack credential, channel name, and that the Slack bot has post permissions.
- MadKudu returns no score: confirm email parameter formatting and that the email exists in MadKudu’s system; check API quota.
- Hunter returns unexpected status: inspect the email format and domain; watch for catch-all or disposable addresses.
- Workflow errors: inspect n8n execution log and re-run test inputs to capture detailed node outputs.
Example use cases
- Early-stage startups that need sales to focus on enterprise-fit leads.
- Marketing teams that want to automate lead nurturing while surfacing high-intent prospects.
- Customer success teams that want to discover upsell opportunities from inbound form responses.
Wrap-up and next steps
Automating lead qualification with n8n, Hunter, and MadKudu speeds up response time, improves SDR efficiency, and ensures sales focuses on the best opportunities. Start with a conservative threshold, test, and iterate based on real conversion data.
Ready to ship this workflow? Set your MadKudu, Hunter, and Slack credentials, test the flow with a sample lead, and activate. If you’d like a copy of the n8n JSON template shown above, or help tuning thresholds and Slack alerts, contact us.
Contact n8nBazar support to get a hand with setup or optimization.