Integrating with Google Sheets via n8n

Why Use n8n with Mailsfinder?

n8n is an open-source workflow automation platform that connects different services and APIs together without requiring you to write complex code. By combining n8n with Mailsfinder and Google Sheets, you can build powerful automation workflows that read prospect lists from a spreadsheet, find and verify email addresses through the Mailsfinder API, and write the results back to your sheet -- all on autopilot.

This integration is ideal for sales teams that manage their prospecting pipeline in Google Sheets and want to eliminate manual copy-paste work between tools.

Prerequisites

Before setting up the workflow, make sure you have the following:

• An active Mailsfinder account with API access (Growth plan or higher)
• Your Mailsfinder API key (found under Settings > API Keys in your dashboard). See the full API documentation for endpoint details
• An n8n instance (either self-hosted or n8n Cloud)
• A Google account with access to Google Sheets

Step 1: Set Up Your Google Sheet

Create a new Google Sheet with the following column headers in Row 1:

first_name | last_name | company | domain | email | status | confidence

Fill in the first_name, last_name, and either company or domain (or both) for each prospect. Leave the email, status, and confidence columns blank -- n8n will populate those automatically.

Step 2: Create the n8n Workflow

Open n8n and create a new workflow. You will need four nodes connected in sequence:

1. Trigger node (Schedule or Manual): Set this to run on a schedule (e.g., every hour) or trigger manually. For testing, use the "Manual Trigger" node.
2. Google Sheets node (Read): Configure this node to read rows from your Google Sheet. Use OAuth2 credentials to connect your Google account. Set the operation to "Read Rows" and filter for rows where the email column is empty.
3. HTTP Request node (Mailsfinder API): This node calls the Mailsfinder email finder endpoint for each row. Configure it as follows:

Method: POST
URL: https://api.mailsfinder.com/v2/find
Headers:
  Authorization: Bearer YOUR_API_KEY
  Content-Type: application/json
Body (JSON):
{
  "first_name": "{{ $json.first_name }}",
  "last_name": "{{ $json.last_name }}",
  "company": "{{ $json.company }}",
  "domain": "{{ $json.domain }}"
}

4. Google Sheets node (Update): Configure a second Google Sheets node to write the Mailsfinder results back to the corresponding row. Map the API response fields to your sheet columns: email from $json.email, status from $json.status, and confidence from $json.confidence.

Step 3: Add Error Handling

To handle rate limits and failed lookups gracefully, add a "Wait" node between the HTTP Request and the Google Sheets Update nodes. Configure the wait time to 1 second between requests to stay well within your API rate limits. Additionally, add an "If" node after the HTTP Request to check if the response status is 200. Route successful responses to the update node and failed responses to a separate error-logging sheet.

Automation Examples

Once the basic workflow is running, you can extend it in several ways:

• Auto-verify found emails: Add another HTTP Request node after the finder node that calls the Mailsfinder verification endpoint. This way, every email is both found and verified in one automated pass.
• Push to CRM: Add a CRM node (HubSpot, Salesforce, or Pipedrive) after the Google Sheets update to automatically create or update contacts with verified email addresses.
• Slack notifications: Add a Slack node to send a summary message to your sales channel every time the workflow completes, reporting how many emails were found and verified.
• Scheduled daily runs: Replace the manual trigger with a Cron trigger that runs once daily. This is useful when your team adds new prospects to the sheet throughout the day and wants emails enriched overnight.

Troubleshooting Common Issues

• Google Sheets authentication error: Ensure your OAuth2 credentials have the correct scopes for reading and writing Google Sheets data. Re-authorize if tokens have expired.
• Empty API responses: If Mailsfinder returns no email for a row, it usually means the combination of name and company did not match any records. Double-check spelling and try adding a domain column for better results.
• Rate limit errors (429): Increase the wait time between requests in your Wait node, or check if your plan's rate limit supports the volume you are processing.

Summary

Connecting Mailsfinder with Google Sheets through n8n creates a hands-free prospecting pipeline. Set up the four-node workflow, add error handling, and extend it with verification, CRM pushes, or Slack notifications to match your team's workflow. Once configured, the automation runs in the background while your team focuses on selling.