Audit reviewed email drafts between Google Sheets and n8n Forms with Code and IF

Quick overview

Find email drafts changed after review. The assigned reviewer checks the full message in an authenticated n8n form and saves that exact version. A manual check compares it with Google Sheets and updates a review queue. The workflow sends no email.

How it works

1. Keep current messages in the Drafts tab. Check drafts reads the drafts, saved review snapshots and existing queue, then compares each draft with its reviewed version.
2. Review a draft lets the assigned reviewer sign in, read the complete recipient, subject, body and source notes, and confirm the exact message. Reviewers need an n8n account with permission to execute the workflow.
3. Before saving, the workflow rereads the draft and existing snapshots. A change made during review requires another look. It reads the saved snapshot back before reporting success.
4. Run Check drafts again after a review. It updates one Review queue row per Draft ID, showing the status, changed fields, reason, next action and check time. Saving a snapshot alone does not refresh the queue.
5. Changes to the recipient, subject, body, source notes, revision or assigned reviewer can require another review. Missing, expired or invalid review records also need attention. Malformed or duplicate IDs stop processing before a write.
6. A Matches result describes the data at the displayed check time. Apply your normal final review before sending. This workflow does not send messages, call an AI model or run on a schedule.

Setup

1. Import the template into n8n. Open the companion sheet and choose File > Make a copy. Keep all three tabs, their names, headers on row 7 and data from row 8. Start with Reviewed snapshots and Review queue empty.
2. In Configure tracker, enter your copied sheet's ID. Select the same Google Sheets connection in all nine Sheets nodes. In each Drafts row, set Required reviewer to that person's n8n sign-in email. In Review a draft, keep n8n User Auth, Require Execute Access and Include User in Output enabled.
3. Use the fictional samples first. Run Check drafts; the three samples should need review. Start Review a draft, review 001 and save its snapshot. Run Check drafts again and inspect that row. Change its recipient, rerun Check drafts and confirm that another review is needed. Keep the workflow unpublished during testing.

Requirements

• An n8n instance supporting the supplied Forms and Code nodes; reviewers with n8n accounts and workflow execute permission; a copied companion Google Sheet; and one Google Sheets connection with access to that copy. Run one review or audit at a time, with at most 100 combined draft, snapshot and retained queue IDs. Your n8n hosting and Google account terms apply.

Customization

• Replace the fictional drafts with your own approved data, preserving column names and unique Draft IDs. Assign the intended reviewer, advance the revision when a draft changes, and choose a review validity of 1 to 90 days. Review form pages expire after 30 minutes. Keep authentication and readback checks enabled.

Additional info

The editable sheet is a review aid, not an immutable audit log. An edit that is completely reversed without advancing the revision may be invisible to a later comparison. Protect access to the sheet, check the latest queue timestamp and make the final sending decision yourself. For a free practice activity on reviewing changes after approval, see Human Approval Gate.