Send 3-7-14 day quote follow-up emails with Gmail and Google Sheets

Quick overview This workflow runs daily to read open quotes from Google Sheets, calculates how many days have passed since each quote was sent, and sends the appropriate 3-, 7-, or 14-day follow-up email via Gmail, then writes a sent date back to the sheet to prevent duplicates. How it works Runs every day at 9am on a schedule trigger. Loads your business details, follow-up day offsets, and email subject/body templates from a preset configuration. Reads all quote rows from a Google Sheets spreadsheet. Keeps only quotes with status set to open, calculates days since sentdate, and selects the next due follow-up (day 3, 7, or 14) that has not been sent yet. Sends a plain-text follow-up email th

Help me set up the n8n workflow "Send 3-7-14 day quote follow-up emails with Gmail and Google Sheets" (https://n8n.io/workflows/16975). It uses: Google Sheets, Gmail, Code. Import the template JSON into my n8n instance, list every credential I need to create, and walk me through testing it.