Overview
A production-ready n8n automation system that continuously monitors a business Outlook inbox, validates incoming emails based on sender and attachment rules, processes documents, and ensures reliable execution through Windows service management. Deployed on a Windows Server 2019 virtual machine and designed to run 24/7 without manual intervention.
The Problem
The business relied on manual email checks to validate incoming customer documents. This led to delays, human errors, and inconsistent handling of missing or incorrect attachments. The system also needed to be reliable enough to handle emails arriving during server restarts or downtime.
Technical Solution
System Architecture
- •n8n workflow with scheduled Outlook inbox polling
- •Sender-based filtering to process only trusted email sources
- •Attachment validation logic to detect required documents
- •Automated file download and folder-based organization
- •XLSX to CSV conversion for downstream system compatibility
- •Windows Server deployment with NSSM-managed background service
Automation Engine
n8n
Email Provider
Microsoft Outlook
Deployment
Windows Server 2019 (VM)
Service Manager
NSSM
File Handling
PDF, DOCX, XLSX → CSV
Results & Impact
100%
Automated email handling
Zero
Manual intervention after setup
Consistent
Document validation and storage
Lessons Learned
Reliability Beats Complexity
Running n8n as an NSSM-managed service ensured stability and automatic recovery without adding unnecessary infrastructure.
Clear Folder Semantics Matter
Separating emails into processed and invalid folders made auditing and debugging significantly easier for non-technical staff.
Automation Needs Ops Thinking
Designing for restarts and downtime was as important as the workflow logic itself.