Tutorial: Automate Email Sending with OpenAI & Gmail in n8n

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Watch on Youtube: https://www.youtube.com/watch?v=NJxkrfBuo8A

Tutorial: Automate Email Sending with OpenAI & Gmail in n8n

In this step-by-step tutorial, you’ll learn how to build a powerful automation workflow in n8n that:

Uses OpenAI to generate professional email content

Parses the email subject and body cleanly

Sends emails securely using the Gmail node with OAuth2 authentication

This is a perfect beginner-friendly project to get hands-on with AI-powered automation and real-world integrations.

What You’ll Build

By the end of this tutorial, you’ll have a workflow that:

1. Starts manually using the Manual Trigger node

2. Uses OpenAI (Chat Model node) to generate a personalized email

3. Parses the AI output into subject and body using a Set or Code node

4. Connects to Gmail via OAuth2 authentication

5. Sends the email using the Gmail → Send Message node

Tools & Integrations Used

• n8n (self-hosted or cloud)

• OpenAI Node (ChatGPT or similar model)

• Gmail Node

• Google Cloud Console (to create Gmail OAuth2 credentials)

Setting Up Gmail in n8n (OAuth2)

To connect Gmail securely, follow these steps:

1. Create a Google Cloud Project:

   Go to Google Cloud Console, create a new project.

2. Enable Gmail API:

   Search for “Gmail API” and click Enable.

3. Create OAuth2 Credentials:

   • Go to APIs & Services > Credentials

   • Click Create Credentials → OAuth client ID

   • Application type: Web Application

   • Add redirect URI: https://your-n8n-domain.com/rest/oauth2-credential/callback (For n8n Cloud, use the provided redirect URL from the Gmail node credential setup)

4. Copy the Client ID & Client Secret

   • Paste them into the Gmail credentials setup inside n8n

   • Authorize the connection and save

According to n8n Gmail Docs:

The Send Message operation supports plain text, HTML, and attachments, and you can dynamically populate the subject, recipient(s), and message content from previous nodes in the flow.

Sending the Email

• Drag the Gmail node into your workflow

• Set Operation to Send Message

• Fill in fields:

  • To: Static email or from previous node

  • Subject: From OpenAI output

  • Text/HTML Body: From OpenAI output

• Optional: Set cc, bcc, and even attach files from prior steps

Perfect For:

• AI & automation beginners

• Recruiters automating outreach

• Developers testing n8n workflows

• Marketers sending dynamic campaign emails