MailMint IMAP Supplier Invoice Emails to Google Sheets via n8n

Turn supplier invoice emails into auditable Google Sheets rows—automatically

This n8n workflow watches an IMAP mailbox for supplier invoices, extracts the invoice fields with MailMint, and appends one verified row per email into Google Sheets—including confidence and the verbatim text each value came from, so you can audit instead of trust.

What this workflow does

• Watches your invoices mailbox using n8n’s built-in Email Trigger (IMAP). Point it at the mailbox your suppliers send to—supporting all three Email Trigger formats.
• Sets your spreadsheet policy in one place: configure the target spreadsheet, the tab, the expected currency, and the amount threshold where a human should review.
• Reads invoice fields with MailMint: the MailMint node is left on Input = Automatic, so it understands the IMAP trigger’s RAW, Resolved, and Simple formats without manual mapping.
• Returns confidence + verbatim extraction for every field. Each extracted value includes:
  • confidence
  • the layer it came from
  • the verbatim text used
• Handles missing required fields: if a required field can’t be found, it routes to the node’s second output so you don’t silently get blank cells.
• Never hard-stops the workflow: if the MailMint API is unreachable, it’s set to continue on failure and writes an error row to the sheet.

Use cases

• Accounts payable teams who currently retype supplier invoices from email into spreadsheets.
• SaaS operators who need repeatable invoice-to-Spreadsheet processing with audit trails.
• Automation engineers building an IMAP → MailMint → Google Sheets workflow for supplier document ingestion.

Technical details

• n8n Email Trigger (IMAP) to watch the mailbox (all three supported formats).
• MailMint for invoice field extraction (Input: Automatic).
• Google Sheets as the destination for appended rows.
• Workflow nodes include if, set, and supporting logic (plus Google Sheets output and canvas-configured policy).