MailCheck - Mail Server Health Monitoring
A minimal, stateless mail server health monitoring service using pure shell scripts with socat as the web server.
Features
- MX Records Check - Verifies mail server configuration
- SSL/TLS Certificate Monitoring - Checks SMTP certificate validity and expiration
- DNS Records - Validates SPF, DMARC, and DKIM records
- Port Connectivity - Tests SMTP (25, 587, 465), IMAP (993), POP3 (995)
- RBL Blacklist Checks - Tests against major spam blacklists (Spamhaus, SpamCop, etc.)
- Open Relay Detection - Security check for misconfigured mail servers
- Simple HTTP Interface - Clean POST-based API with configuration panel
- Performance Metrics - Response time tracking for all checks
- Highly Configurable - Frontend panel + environment variables for DKIM selectors, RBL servers, DNS servers
- Fully Dockerized - Pure shell, no Python/Node.js required
- Lightweight - Alpine-based, <50MB image