How to Auto-Draft Email Replies from a Form with Zapier and GPT

When someone fills out your contact form, you usually have to read it and write a reply by hand. This guide catches the submission with a Zapier webhook, asks GPT to draft a warm, on-brand response, and drops the draft into Gmail so you only need to review and send.

What you need

• A form tool that supports webhooks (Typeform, Jotform, or Tally)
• A Zapier account and an OpenAI API key
• A Gmail or Outlook account connected in Zapier

Step 1: Point the form webhook at Zapier

Create a Catch Hook trigger in Zapier and copy its URL. In your form tool's settings, add that URL as a webhook destination so each submission is POSTed to Zapier.

Step 2: Ask GPT for a draft

Add an OpenAI action (or a Webhooks POST step) that sends the form message to the Chat Completions endpoint with a system prompt describing your tone.

{
  "model": "gpt-5-mini",
  "messages": [
    {
      "role": "system",
      "content": "You are a friendly support agent. Write a short, helpful email reply. Sign off as 'The Setuproll Team'."
    },
    {
      "role": "user",
      "content": "Customer name: {{name}}\nTheir message: {{message}}"
    }
  ]
}

Step 3: Create a Gmail draft

Add a Gmail action with the Create Draft event. Set the To field to the form's email value, write a subject line, and map the Body to the OpenAI output field choices.0.message.content.

Step 4: Turn the Zap on

Publish the Zap and submit a test entry through your real form. Open Gmail and check the Drafts folder.

Result: every inquiry gets a thoughtful draft within seconds, and you keep full control because nothing sends until you click send.