RBL Sentinel

Early-warning and appeal assistant for IPs silently blacklisted by RBLs

Problem

Indie site owners get caught in ASN-wide blacklists like UCEPROTECT Level 3 even when their own IP did nothing wrong, quietly killing site traffic and email deliverability. These listings rarely notify you, so you only find out when users complain or traffic drops. Appealing means hand-checking dozens of RBL sites one by one.

Solution

A scheduled monitoring service: register your domains/IPs and it checks major RBLs and ASN-level lists daily, alerting you via email or webhook the moment you're listed, with a ready-to-send appeal template per list. A passive-DNS self-check page lets you confirm an ASN-wide false positive in seconds.

Users

Indie developers, small SaaS operators, and SMB IT running their own mail servers

MVP

Domain/IP registration with ownership verification; daily polling of 20-30 major RBLs with ASN-level false-positive detection; email/Webhook alerts with appeal templates; read-only self-check web page; history dashboard showing list/removal timeline

Revenue

Free for one domain; subscription at $5-15/month for multiple sites plus API and team alerts

Why now

The UCEPROTECT episode on HN shows ASN-wide false positives are a common but ignored pain; monitoring fits a cron job and a small DB, ideal for a solo developer