Email Infrastructure Monitoring

Monitor blocklists, server uptime, and SMTP health to catch deliverability issues before they impact your campaigns.

Blocklist Monitoring

Check your IP addresses and domains against 50+ major email blacklists including Spamhaus, SORBS, Barracuda, and more. Get instant alerts when you're listed.

What We Monitor

  • Spamhaus (ZEN, DBL, SBL) - Most influential blocklist
  • SORBS - Open relays and spam sources
  • Barracuda - Enterprise email security
  • URIBL & SURBL - Domain and URL blacklists
  • SpamCop - User-reported spam tracking
  • Plus 45+ regional and specialized DNSBLs

Why It Matters

Being listed on a major blocklist can instantly tank your deliverability. Spamhaus alone influences filtering decisions for millions of mailboxes worldwide. Early detection means faster delisting and minimal damage to your sender reputation.

Uptime Monitoring

Track SMTP server availability, DNS resolution speed, and SSL certificate health. Get notified immediately when your mail infrastructure goes down.

Monitoring Checks

  • SMTP Connectivity - Test ports 25, 587, 465
  • DNS Resolution - Monitor MX, SPF, DKIM lookups
  • SSL Certificates - Track expiration dates (30-day warnings)
  • Response Times - Measure server latency and performance
  • Server Banners - Verify proper SMTP identification

Alert Types

Get instant notifications via email, Slack, or webhook when servers go offline, certificates near expiration, or response times degrade. Set custom thresholds and escalation policies for different severity levels.

SMTP Server Health Checks

Validate SMTP server configuration, test connectivity, verify TLS support, and ensure proper MX record setup for reliable email delivery.

Server Validation

  • MX Records - Verify mail exchanger configuration and priority
  • STARTTLS - Check encryption support and certificate validity
  • Open Relay - Test for misconfigured relay settings
  • Server Capabilities - Check ESMTP features (SIZE, AUTH, PIPELINING)
  • Reverse DNS - Validate PTR records match server hostname

Common Issues Detected

Identify misconfigured MX records, expired SSL certificates, lack of TLS support, open relay vulnerabilities, and missing reverse DNS. Each issue includes detailed remediation steps and priority levels.

TLS Security Monitoring

Monitor STARTTLS configuration, MTA-STS policies, and TLS-RPT reporting to ensure encrypted email transport and security compliance.

TLS Checks

  • STARTTLS Support - Verify encryption is available and functional
  • MTA-STS - Check policy mode (testing, enforce, none)
  • TLS-RPT - Monitor reporting configuration for TLS failures
  • Certificate Validity - Ensure certs are valid and not expired
  • Cipher Suites - Check for weak or deprecated encryption

Why TLS Matters

Gmail and other major providers require TLS encryption for secure email delivery. MTA-STS prevents downgrade attacks by enforcing TLS. TLS-RPT provides visibility into encryption failures that could indicate attacks or misconfigurations.

Email Monitoring Best Practices

Check Blocklists Daily

Monitor all sending IPs and domains against major DNSBLs at least once per day. Set up automated checks every 6 hours for high-volume senders. Quick detection means faster delisting.

Monitor Server Uptime 24/7

Use 5-minute check intervals for critical SMTP servers. Monitor from multiple geographic locations to catch regional issues. Set up escalation policies for extended outages.

Track SSL Certificate Expiration

Get alerts 30, 14, and 7 days before certificate expiration. Automate renewal with Let's Encrypt or similar services. Test certificate validity after each renewal.

Configure Alert Routing

Send critical alerts (blocklisting, server down) to on-call teams via PagerDuty or Opsgenie. Route warnings (degraded performance) to email. Archive all alerts for historical analysis.