n8n Gmail Quote Follow-Ups with Google Sheets & OpenRouter

Automated Gmail quote follow-ups—powered by Google Sheets + OpenRouter

This n8n workflow checks customer replies in Gmail for each sent quote stored in Google Sheets, then uses OpenRouter to classify responses or draft timely follow-up emails—updating quote status and follow-up counts automatically.

What this workflow does

• Runs daily at 9:00 and loads follow-up settings (timing thresholds, tone, and owner email).
• Reads open quotes from the Google Sheets “Quotes” tab, filtering for rows where Status is sent or followed up.
• Searches Gmail per quote to find the most recent customer message since the quote’s Sent Date.
• Determines next action based on days since sent, follow-up count, and defined windows:
  • Wait (no action yet)
  • Send a follow-up email
  • Mark the quote as gone cold when overdue with no response
  • Treat the quote as replied when a customer message is detected
• On customer replies, fetches the reply from Gmail, uses OpenRouter to classify intent and draft a suggested response, emails a summary to the owner, and updates Google Sheets (status + last contact date).
• On follow-up due, generates a short follow-up via OpenRouter, sends it through Gmail, and updates Follow-ups, Status, and Last Contact in Google Sheets.

Use cases

• SaaS teams following up on quote requests without manually checking inboxes.
• Sales ops or founders using Google Sheets as the CRM-lite pipeline for quotes.
• Service businesses needing consistent, rules-based email follow-ups with reply summaries to the owner.

Technical details

• Google Sheets OAuth2 connection (reads/writes the “Quotes” tab columns like Quote ID, Status, Follow-ups, Last Contact).
• Gmail integration to search for messages and send follow-ups.
• Workflow logic using nodes such as set, code, filter, switch, and sticky note.
• OpenRouter for drafting follow-up emails and classifying reply intent + suggested responses.