# Protect Gmail AI email workflows from prompt injection: n8n workflow

> Started by an arriving email, and works across Gmail and Google Sheets. It hands the judgement calls to Gemini.

Source: https://millionrounds.com/workflow/protect-gmail-ai-email-workflows-from-prompt-injection (Millionrounds; every figure on the page links to its filing or article)

[Automation library](https://millionrounds.com/workflows) · [Data collection](https://millionrounds.com/workflows?category=Data+collection#library)

# Protect Gmail AI email workflows from prompt injection

Started by an arriving email, and works across Gmail and Google Sheets. It hands the judgement calls to Gemini. 14 steps, 2 branches: a working afternoon to understand properly.

Medium Calls a model: Gemini

[Download free](https://millionrounds.com/login?next=%2Fapp%2Fworkflow%2Fprotect-gmail-ai-email-workflows-from-prompt-injection)

**14 steps** Medium: a working afternoon

**2** Branches: places the flow splits

**0** Loops or waits

**2** Services it connects to

## The flow

Starts it 1 Model 1 Logic 7 Service 5

The steps in the order they run, from what starts it.

- 1 **Gmail Trigger: New email for AI safety check** Gmail trigger *Starts it*
- 2 **Set config: Security settings** Set *Logic*
- 3 **Code: Normalize Gmail message** Code *Logic*
- 4 **Code: Detect prompt injection risk** Code *Logic*
- 5 **IF: Block high-risk email** If *Logic*
- 6 **Code: Build blocked audit log** Code *Logic*
- 7 **Gemini: Safely analyze email** Google Gemini *Model*
- 8 **Sheets: Log blocked email** Google Sheets *Service*
- 9 **Code: Parse AI result and finalize risk** Code *Logic*
- 10 **Gmail: Create manual review draft** Gmail *Service*
- 11 **Sheets: Log analyzed email** Google Sheets *Service*
- 12 **Switch: Route by safety result** Switch *Logic*
- 13 **Gmail: Create safe reply draft** Gmail *Service*
- 14 **Gmail: Create human review draft** Gmail *Service*

## How it's built

- **Starts on:** An arriving email
- **Steps:** 14, with 2 branches
- **Size:** Medium: a working afternoon
- **Connects to:** Gmail, Google Sheets
- **Model:** Gemini

## Questions

What does it need to run?

An n8n account, plus your own Gmail and Google Sheets accounts, and a key for Gemini. You connect your own accounts after importing it; none are included.

What starts it?

It starts on an arriving email.

Does it use AI?

Yes. It calls Gemini. Model calls are billed by the provider, not by n8n.

How long does it take to set up?

Plan an afternoon. 14 steps is enough that you should read each one before running it.

How do I import it?

Copy the workflow, open a new workflow in n8n and paste. The steps appear on the canvas, ready for your own accounts.

**Before you run it**

Nothing here has been tested by us. It is somebody's working automation, read and described from its own steps. Treat the connections it wants as a list of accounts it will touch, and read the 14 steps before you point it at anything that matters.

## Run it in n8n

- **Create your n8n account** Free to start. n8n is where the workflow runs. [Create an n8n account ↗](https://millionrounds.com/n8n)
- **Download the workflow** Free with a Millionrounds account. [Download free](https://millionrounds.com/login?next=%2Fapp%2Fworkflow%2Fprotect-gmail-ai-email-workflows-from-prompt-injection)
- **Paste it into n8n** Open a new workflow in n8n and paste. Then connect your own accounts.

Stored with the author's traces removed: canvas notes, instance identifiers, saved credential names and any live document they had left behind.

## Connects to

Each opens the other workflows that use it.

[Gmail](https://millionrounds.com/workflows?service=Gmail#library)[Google Sheets](https://millionrounds.com/workflows?service=Google+Sheets#library)

## Workflows like it

Also data collection, with the same services where possible, closest in size first.

- [**& analyze n8n workflows from GitHub with OpenAI** 14 steps · calls a model · Google Sheets, Notion](https://millionrounds.com/workflow/and-analyze-n8n-workflows-from-github-with-openai)
- [**AI agent with Google Sheets** 14 steps · calls a model · Google Sheets](https://millionrounds.com/workflow/ai-agent-with-google-sheets)
- [**Anonymize & reformat CVs with Gemini and Google Sheets** 14 steps · calls a model · Google Drive, Google Sheets](https://millionrounds.com/workflow/anonymize-and-reformat-cvs-with-gemini-and-google-sheets)
- [**Automate GPT-4o fine-tuning with Google Sheets and Airtable** 14 steps · calls a model · Airtable, Google Sheets](https://millionrounds.com/workflow/automate-gpt-4o-fine-tuning-with-google-sheets-and-airtable)
- [**Automate Instagram carousel creation with OpenAI** 14 steps · calls a model · Google Sheets](https://millionrounds.com/workflow/automate-instagram-carousel-creation-with-openai)
- [**Automate Twitter and LinkdIn with Gemini and Google Sheets** 14 steps · calls a model · Google Sheets, LinkedIn](https://millionrounds.com/workflow/automate-twitter-and-linkdin-with-gemini-and-google-sheets)