Automate Lead Scoring and Slack Alerts with n8n, MadKudu & Hunter

What this workflow does

This workflow checks new lead emails automatically.

It verifies if emails are good, scores them based on company fit, and only sends alerts for high-quality leads.

Less time is wasted on bad or weak leads.

Sales teams get notified only about interesting prospects.

Tools and services used

• n8n Form Trigger: Captures submitted lead emails.
• Hunter.io API: Checks if email addresses are valid and safe.
• MadKudu API: Scores leads using behavioral and company data.
• Slack API: Posts messages to sales channels about good leads.

Workflow Inputs, Processing, and Outputs

Inputs

• A person submits their business email through a web form linked to Form Trigger.

Processing Steps

• Email Verification: The Hunter node validates email authenticity in real time.
• Validation Check: An If node filters only emails marked valid by Hunter.
• Lead Scoring: An HTTP Request calls MadKudu’s API to get a customer fit score.
• Score Filtering: Another If node processes leads with a fit score over 60 to the next step.

Outputs

• A Slack message with lead details is sent to the #interesting_leads channel via the Slack node.
• Leads with invalid or low scores are ignored automatically.

Beginner step-by-step: How to use this workflow in n8n for production

Step 1: Import the workflow

1. Download the workflow using the Download button on this page.
2. Inside the n8n editor, choose “Import from File” and upload the downloaded workflow JSON.

Step 2: Configure credentials and settings

1. Add Hunter.io API Key credential for email verification.
2. Add MadKudu API Key credential in the HTTP Request node header.
3. Set Slack API credential with a bot token allowed to post in the chosen channel.
4. Update any IDs, emails, channel names, or folder names to match your setup.

Step 3: Test the workflow

1. Trigger the form by submitting a test valid email through the webhook URL.
2. Confirm Hunter returns “valid” status, MadKudu returns a score, and Slack sends a message if the score > 60.

Step 4: Activate for production

1. Once tested, switch the workflow status from draft to active.
2. Share the webhook or embed the form to start real lead processing.

Following these simple steps activates lead automation without building the workflow from scratch.

Consider self-host n8n for full control over data and uptime.

Common problems and edge cases

• If emails fail verification, the workflow stops quietly without sending messages.
• Invalid API keys cause Hunter or MadKudu nodes to error; check keys carefully.
• Low scores below 60 will not notify Slack, preventing noise.
• Slack posting errors happen with incorrect channel name or missing bot permissions.

Always test various email cases to confirm paths work as expected.

Customize the workflow for your needs

• Change the email score threshold by editing the If node condition.
• Alter the Slack message text using expressions to show more or less lead info.
• Replace Form Trigger with other webhook triggers from tools like Typeform or Google Forms, keeping the same email JSON mapping.
• Add extra conditions after MadKudu’s scoring to filter by company size or location.
• Improve email validation by integrating domain or MX record checks using extra HTTP nodes.

Lead alert Slack message example

Use this exact message in the Slack node to notify on hot leads:

=⭐ 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 }}.


{{ $('Score lead with MadKudu').item.json.properties.customer_fit.top_signals_formatted }}

This expression inserts personal and company info plus top scoring signals.

Summary

✓ Automatically filters valid business emails.

✓ Scores leads and detects high-potential customers.

✓ Posts Slack alerts only for best leads, cutting wasted effort.

✓ Helps sales teams focus fast on valuable prospects.

→ Saves about 10 hours of manual lead triage weekly.

→ Streamlines lead qualification with simple n8n automation.