Gmail draft replies written by GPT for mail that needs one

Gmail draft replies written by GPT for mail that needs one

An n8n workflow that writes draft replies in your Gmail. Each new email is first judged by a model: does it need an answer?
Marketing mail does not. For the mail that does, a second model writes a reply and Gmail saves it as a draft in the same
conversation. Nothing is sent. You read each draft, change it and send it yourself.

What is inside

• workflow.json: the workflow as n8n exports it, twelve nodes. Four are sticky notes with short titles. It holds no
  credential.
• README.md: these notes.

What we changed from the original copy

• The first model asked for gpt-4o, which OpenAI shuts down on 14 January 2027. OpenAI Chat now asks for
  gpt-6-luna, the replacement OpenAI names. Its temperature of 0 is gone, because the model's page does not list a
  temperature setting.
• The reply model asked for gpt-4-turbo, which OpenAI shut down on 23 October 2026. OpenAI Chat Model now asks for
  gpt-5.6-sol, the replacement OpenAI names.
• The node that saves the draft was called Gmail - Create Draft. It is now Create Gmail Draft.
• The links to the author's Gmail and OpenAI credentials are gone.

Before you start

• A Gmail account you can connect to n8n with OAuth2.
• An OpenAI API key.

Set it up

1. In n8n, create a workflow, open its menu and choose Import from File. Pick workflow.json.
2. Add a Gmail OAuth2 credential. Select it in Gmail Trigger and in Create Gmail Draft.
3. Add an OpenAI credential and select it in OpenAI Chat and in OpenAI Chat Model.
4. Read the instructions in Generate email reply. They set the tone, the greeting and the sign-off, so change them to
   sound like you.
5. Publish the workflow. Gmail Trigger checks your mailbox every minute.
6. Send yourself a question from another address and open your Drafts folder.

How a run goes

1. Gmail Trigger fetches each new email that does not come from you, using the search -from:me, and parses its
   headers and its text.
2. Assess if message needs a reply asks OpenAI Chat whether the message needs an answer and expects JSON with one
   true or false value. JSON Parser checks the shape. Marketing emails are told to count as not needing one.
3. If Needs Reply lets only the true cases through.
4. Generate email reply asks OpenAI Chat Model for a reply. The instructions ask for a business casual tone, a
   greeting of "Hello," and a sign-off of "Best,". For a yes or no question it writes two replies, one affirmative and one
   negative. Where it does not know an answer, it leaves a placeholder such as [YOUR_ANSWER_HERE].
5. Create Gmail Draft saves the reply as an HTML draft in the same conversation, with the subject Re: and the
   original subject, addressed to the sender.

Change the result

• Which mail is looked at: the search in Gmail Trigger. Add terms to skip newsletters or certain senders.
• What counts as needing a reply: the message in Assess if message needs a reply.
• The tone, the language and the rules of the reply: the message in Generate email reply.
• The models: OpenAI Chat and OpenAI Chat Model.

Good to know

• Nothing is sent. Every reply is a draft.
• Every new email is one model call, and each email that needs a reply is a second one. All of it goes to OpenAI.
• The search -from:me also matches automatic mail from other services, so the first model decides what needs an
  answer. Narrow the search if you want fewer calls.
• The draft is addressed to the email's From header and joins its thread.
• The reply model may invent details. Read each draft before you send it.
• Mindket did not run this workflow against Gmail or OpenAI. These notes follow n8n's published node code and OpenAI's
  deprecations page, read on 12 November 2026.