BLACKLIST

Blacklist (DNSBL) monitor

Checks whether your host's IP appears on common email blacklists. Critical for any service that sends transactional or marketing email.

What it checks

Resolves your target to an IPv4 address and performs a reverse-IP DNS lookup against each configured DNSBL. If any list returns a record, your IP is listed and the check is DOWN. The alert names which list.

Default lists

  • Spamhaus ZEN (zen.spamhaus.org) — combined SBL + XBL + PBL.
  • SpamCop (bl.spamcop.net) — IPs reported through SpamCop's user feedback loop.
  • Barracuda (b.barracudacentral.org) — IPs Barracuda has observed sending spam.

Operating tip

Run this against the IP of your mail server, not your application server. The alert tells you which list flagged you — most have a self-service delisting form once you fix the underlying issue.

Create one via the API

curl https://monitorah.com/api/v1/monitors \
  -X POST \
  -H "Authorization: Bearer mon_live_…" \
  -H "Content-Type: application/json" \
  -d '{
  "name": "My BLACKLIST check",
  "type": "BLACKLIST",
  "target": "1.2.3.4",
  "config": {
    "blacklists": [
      "zen.spamhaus.org",
      "bl.spamcop.net"
    ]
  }
}'

Full reference for this endpoint →

Create a BLACKLIST monitor → All docs