Your public IP, with the checks that matter for mail delivery
This page auto-detects the IP you're connecting from and runs the checks an email admin needs day-to-day: the RDAP record (ASN, network, country, abuse contact), the PTR and FCrDNS status (the lightweight authentication mail servers run before accepting SMTP), an IPv6 connectivity test, and a scan against the major DNSBL/RBL blocklists. Results stream in as each check finishes. Your IP appears immediately and everything else fills in below.
Each result links into the deeper tool with the IP (or the PTR-derived domain) already filled in. A DNSBL hit drops you on the full blacklist breakdown, an FCrDNS failure links straight to the FCrDNS checker, and a mail-server PTR offers prefilled SPF, DMARC, and MX lookups for the same domain.
Privacy: your IP is only shown back to you and used to run the queries on this page. We don't store it. We deliberately skip city-level GeoIP. RDAP country data is reliable, commercial city databases aren't.
What's My IP?
We've detected your public IP from this connection. Below: ASN, PTR, FCrDNS, IPv6 connectivity, and DNSBL status, plus next-step links depending on what the checks return.
216.73.217.152
Frequently Asked Questions
Common questions about public IPs, FCrDNS, IPv6, and DNSBLs.
Is this the IP my mail server actually sends from?
Only if you're loading this page from the same network your mail server runs on. The IP shown here is whichever address this browser session is using to reach tamingdns.com. If your mail server lives on a different host, VPS, or hosting provider, run the checks against its public IP via IP Info or Reverse DNS.
What is FCrDNS and why does it matter?
Forward-Confirmed reverse DNS: the PTR for the IP resolves to a hostname, and that hostname's A/AAAA record resolves back to the same IP. Most large receivers (Gmail, Microsoft, Yahoo and friends) reject or heavily penalise SMTP connections without a passing FCrDNS check. Failing it commonly produces SMTP 550 5.7.25.
Why does the IPv6 test sometimes show "broken"?
The test fetches a JSON endpoint over a hostname that only has an AAAA record. If your network advertises IPv6 capability but the connection times out, your IPv6 path is misconfigured somewhere. Common culprits: stale router advertisements, ISP IPv6 in transit but not at your edge, or a firewall blocking outbound IPv6. For mail senders this matters because Google and others will refuse IPv6 SMTP without a working IPv6 PTR + FCrDNS.
Why don't I see a city or region?
RDAP only exposes the country an IP block is registered in. City and region level GeoIP needs a commercial database like MaxMind or IP2Location. Those are built from inference rather than registry data, and they're unreliable for IPv6, mobile carriers, and cloud ranges. We deliberately don't ship that data here.
I'm listed on a DNSBL — what now?
Click through to the full blacklist breakdown from the result above. Each listing has a direct link to the operator's delisting form. Before you request delisting, find and fix the underlying cause. Sending mail from a still-compromised IP just gets you relisted within hours.
My PTR doesn't match the domain I send mail from. Is that bad?
Not on its own. What matters is that the PTR resolves to something sensible (not a generic ISP/hosting auto-PTR like 5-23-45-67.broadband.example.net) and that the forward record points back to the same IP. The sending domain in SMTP MAIL FROM and the DKIM/SPF/DMARC alignment is what receivers actually authenticate against. A mismatched PTR is only a red flag if it looks like dynamic or residential space.