Blacklist & Reputation Monitoring
Know immediately if your IP or domain is blacklisted.
Blacklist listings silently destroy email deliverability. A single compromised account, a spam complaint spike, or an inherited reputation problem can land your sending IPs on major blocklists before you know it's happening. NetTests checks your IPs and domains against 50+ blocklists on a schedule and alerts you the moment a new listing appears.
Blacklist listings are invisible until the damage is done
When a sending IP is listed on a major blocklist, messages destined for ISPs that subscribe to that list begin failing silently. Recipients may never see a bounce — messages simply disappear. Without active monitoring, the first sign of a blacklist listing is often a sharp drop in open rates or a client reporting that they aren't receiving emails, by which point significant damage to sender reputation may have occurred.
Blacklist monitoring provides the earliest possible warning. By checking against all major blocklists on a schedule, NetTests detects new listings within hours — giving you time to investigate the cause, remediate the issue, and begin the delisting process before the impact on deliverability becomes severe.
Key features
50+ blocklist checks
Check against Spamhaus, SORBS, Barracuda, SpamCop, and dozens of other widely-used blocklists.
IP and domain monitoring
Monitor sending IP addresses and domain names independently — both can be listed on different blocklists.
Immediate new-listing alerts
Receive notifications as soon as a new listing is detected — before deliverability impact accumulates.
Listing history
Track when your IPs and domains have been listed and delisted over time — useful for diagnosing recurring reputation problems.
Free reputation tools
Monitor your reputation before customers notice
NetTests checks your IPs and domains against 50+ blocklists on a schedule and alerts you immediately on any new listing.
Start monitoring free →