Reputation

Check an IP against blocklists

Test an IPv4 address against common DNS blocklists (RBLs) to see whether mailers are rejecting it.

When to use it

Use this when

  • Your mail server’s IP may be blocklisted and outbound mail is being rejected.
  • You are vetting an address’s reputation before you start sending from it.

Steps

Do this

  1. Enter the IPv4Open Blocklist and enter the address. dnsbin queries each blocklist zone for a listing.
  2. Read per-zone resultsEach RBL reports listed, clear, or unavailable; a listing usually carries a reason code from that provider.
  3. Request delistingFollow up with the listing provider — delisting is handled by each blocklist operator, not dnsbin.

Examples

Copyable commands

REST — listed test address
curl 'https://dnsbin.ca/api/v1/dnsbl?ip=127.0.0.2'
REST — a real address
curl 'https://dnsbin.ca/api/v1/dnsbl?ip=8.8.8.8'

Operational notes

Keep in mind

  • 127.0.0.2 is the conventional test address that every well-behaved RBL lists, so it’s useful to confirm the tool works.
  • Some zones (such as Spamhaus) block queries from large public resolvers and report as unavailable rather than clean.
  • Listings and delisting policies are per-provider; dnsbin only reports what each zone returns.