Validate Leads Email Addresses with Hunter.io and Google Sheets

How it works:

This project automatically verifies lead email addresses stored in Google Sheets using Hunter.io . It checks each email's validity and writes back the results—including confidence scores, verification status, and metadata—so your outreach lists are always clean and reliable.

This workflow runs daily, reads from a source sheet, verifies emails via API, and writes results into another sheet. No manual checking. No wasted leads.

Step-by-step:

• Schedule Trigger:
  The workflow is scheduled to run automatically once per day, but you can also run it manually when needed.

• Fetch Emails:
  Reads emails from a Google Sheet (named Sheet1) with columns like Email, FirstName, LastName, and Company.

• Data Cleaning:
  Filters out blank or invalid email formats before verification to save API usage.

• Hunter.io Verification:
  Each email is passed to Hunter.io 's /email-verifier API, returning status (valid, invalid, risky), SMTP check, score (0–100), and disposable flag.

• Format Results:
  The API response is converted into a human-readable summary like:
  ✅ Valid (96% confidence) or ❌ Invalid / Risky

• Write to Sheet:
  The verified results are written back into your output Google Sheet—either appending new rows or updating existing ones.

Setup instructions:

• Google Sheets:
  Use a sheet named Sheet1 and ensure it includes these columns:
  Email, FirstName, LastName, Company.

• Hunter.io Key:
  Sign up at hunter.io .

Go to Dashboard → API → Copy your key

In n8n, open the Email Verifier node → Create Credential → Paste your API key → Save