AbuseBox: a self-hosted blacklist monitor with its own resolver

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AbuseBox checks the IP addresses and domains you own against 24 DNS blacklists on a schedule, and alerts you by email, Slack, Discord or webhook when something changes. It also checks SSL and domain expiry, SPF, DKIM and DMARC, DNS records and uptime. The maker built it after twice learning their mail server was blacklisted only when people's mail bounced.

The maker found that Spamhaus doesn't answer big public resolvers honestly: Cloudflare returns a refusal code and Google returns nothing, which looks like "not listed". So AbuseBox ships its own Unbound resolver and tests each list against the RFC 5782 test addresses, discarding answers from any list that gets them wrong. The project is three and a half years old; much of the recent code was written with Claude Code and reviewed by the maker, who checked the DNS behaviour by hand.