What is a blocklist monitoring service?

A blocklist monitoring service continuously checks your sending infrastructure against multiple blocklists and alerts you when listings occur. This provides early warning before problems escalate.

Services like MXToolbox, Validity (formerly Return Path), GlockApps, and 250ok offer monitoring that checks dozens of blocklists regularly. When a listing is detected, you receive an alert via email, SMS, or dashboard notification.

Monitoring services typically check both IPs and domains across various list types: IP blocklists, domain blocklists, and URI blocklists. Comprehensive coverage ensures you catch any listing that might affect deliverability.

Early detection is valuable because it lets you address problems before widespread damage occurs. A listing caught in hours is easier to manage than one discovered after days of delivery failures.

Monitoring is your early warning system. It catches problems while they are still small enough to manage.