Send bulk email campaigns with Gmail/SMTP and Postgres reputation-safe timing

Overview

This workflow automates bulk email campaigns with built-in validation, deliverability protection, and smart send-time optimization.

It processes CSV leads, validates emails, enriches data, and schedules campaigns intelligently. Emails are sent using controlled inbox rotation, while engagement tracking and analytics continuously improve performance.

How It Works

1. Campaign Input Receives campaign data and CSV leads via webhook.

2. Lead Processing Extracts CSV data, splits leads, and validates email format.

3. Domain & Quality Checks Verifies domains using MX records and filters invalid leads.

4. Lead Enrichment Adds timezone, domain type, and engagement score for better targeting.

5. Lead Storage Stores valid leads and separates invalid ones for tracking.

6. Campaign Execution Scheduler fetches active campaigns and selects top leads.

7. Send Optimization Calculates best send time per lead based on timezone and historical performance, while selecting inboxes within sending limits.

8. Email Delivery Waits until optimal time and sends emails using selected inbox.

9. Tracking & Logging Logs sent emails and updates inbox usage statistics.

10. Event Tracking Captures opens, clicks, replies, and bounces via webhook.

11. Performance Analytics Updates campaign stats and analyzes engagement trends.

12. Continuous Optimization Updates send-time rules to improve future campaign performance.

Setup Instructions

• Connect webhook for campaign and CSV upload
• Configure send limits, delays, and MX API
• Set up Postgres with required tables
• Connect Gmail or SMTP for sending
• Configure event webhook for tracking
• Enable campaign and analytics schedulers
• Test with sample campaign before activating

Use Cases

• Running cold email campaigns at scale
• Improving email deliverability and sender reputation
• Automating lead validation and enrichment
• Optimizing send times based on engagement data
• Managing multi-inbox outbound systems

Requirements

• n8n instance with webhook support
• Postgres database
• Gmail or SMTP email account(s)
• MX record lookup API (e.g., Google DNS)
• Email tracking system or webhook integration

Notes

• Inbox rotation and throttling help prevent spam and protect reputation.
• Engagement-based lead scoring improves campaign performance.
• Send-time optimization is continuously refined using real data.
• You can extend this workflow with personalization or AI-generated emails.