https://mrdns.com/

Mr.DNS Mr.DNS

  * DNS Lookup
  * What is My IP
  * Network Tools
    DNS & IP
    DNS Propagation Check DNS changes across 7 global resolvers 
    DNSSEC Checker Verify DNSSEC chain of trust Whois Domain and IP
    registration details Port Checker Test if a TCP port is open or
    closed Blacklist / RBL Check Check IPs and domains against 15+
    blocklists
    Connectivity & Web
    Ping Send ICMP echo requests, measure RTT Traceroute Trace
    network path hop-by-hop SSL Certificate Check Inspect certificate
    details, expiry, and chain HTTP Headers Inspect response headers
    and redirect chain HTTP/2 & HTTP/3 Check modern protocol support
    and HSTS
  * Email Tools
    Check & Validate
    Email Health Check Combined SPF + DMARC grade SPF Checker 
    Validate & expand SPF records DKIM Checker Validate DKIM public
    keys DMARC Checker Validate & diagnose DMARC records MTA-STS
    Checker Validate MTA-STS policy and DNS record
    Diagnose & Build
    BIMI Checker Validate BIMI record and logo SVG Email Header
    Analyzer Trace delivery path and auth results
    Generators
    SPF Generator Build & publish SPF records DMARC Generator Build &
    publish DMARC records

Recent Lookups
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DNS & Network Tools

Free, fast diagnostic tools for DNS, email authentication, network
security, and more.

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DNS Tools

 

DNS Lookup

Query A, AAAA, MX, TXT, NS, SOA, CNAME, PTR, CAA, SRV, TLSA, HTTPS,
MTA-STS, BIMI and more. Results come directly from authoritative
nameservers.

Look Up DNS Records
 

DNS Propagation Checker

Query 7 global public resolvers simultaneously to see whether your
DNS changes have propagated worldwide.

Check Propagation
 

DNSSEC Checker

Verify the DNSSEC chain of trust. Check DS, DNSKEY, and RRSIG records
to confirm cryptographic signing is properly configured.

Check DNSSEC
 

Whois

Look up structured RDAP registration data for any domain or IP --
registrar, status, expiry dates, nameservers, and contacts.

Whois Lookup

Network Tools

 

My IP Address

Detect your public IPv4 and IPv6 addresses with geolocation, ISP
name, and a live map.

View My IP
 

Ping

Send ICMP echo requests to any hostname or IP and see real-time
round-trip times and packet loss statistics.

Ping a Host
 

Traceroute

Trace the network path hop-by-hop with real-time results and
geolocation data for each router along the route.

Run Traceroute
 

Blacklist / RBL Check

Check an IP address or domain against 15+ major DNS-based blocklists
in parallel.

Check Blacklists
 

SSL Certificate Check

Inspect SSL/TLS certificate details, expiry date, SANs, key info, and
certificate chain for any hostname.

Check Certificate
 

HTTP Headers

View HTTP response headers and redirect chains. Highlights security
headers and flags missing ones.

Check Headers
 

HTTP/2 & HTTP/3 Checker

Test whether a site supports HTTP/2 and HTTP/3. Checks ALPN
negotiation, Alt-Svc advertisement, HTTPS redirect, and HSTS
configuration.

Check Protocol Support
 

Port Checker

Test whether a TCP port is open or closed on any hostname or IP
address. Grabs server banners for SSH, SMTP, FTP, and more.

Check a Port

Email Tools

 

Email Health Check

Get a combined SPF + DMARC health grade (A-F) with a per-check
breakdown and actionable recommendations for your domain.

Check Email Health
 

SPF Checker

Look up and validate SPF records for any domain. Recursively expands
all include chains and flags errors.

Check SPF Record
 

DMARC Checker

Look up and validate DMARC records for any domain. Every tag is
explained with validation status and warnings.

Check DMARC Record
 

DKIM Checker

Look up and validate DKIM public keys for any domain and selector.
Checks key size, flags, and configuration.

Check DKIM Record
 

Email Header Analyzer

Paste raw email headers to trace the delivery path, check SPF/DKIM/
DMARC results, and find routing delays.

Analyze Headers
 

SPF Generator

Build a valid SPF record for your domain. Select email providers,
enter IP ranges, and generate a ready-to-publish TXT record.

Build SPF Record
 

DMARC Generator

Build a valid DMARC record for your domain. Set policy, reporting
URIs, and alignment options.

Build DMARC Record
 

MTA-STS Checker

Validate MTA-STS DNS records and policy files. Check mode, max_age,
MX coverage, and policy file reachability.

Check MTA-STS
 

BIMI Checker

Validate BIMI DNS records, fetch and preview the SVG brand logo, and
check VMC certificate URLs.

Check BIMI
Mr.DNS Mr.DNS

Free DNS, network, and email diagnostic tools for developers, network
engineers, and email admins.

Partners GeneratorLabs -- RBL & Cert Monitoring GoodTLS -- TLS
Configuration Guides
DNS & IP

  * DNS Lookup
  * DNS Propagation
  * DNSSEC Checker
  * My IP Address
  * Whois

Network & Web

  * Blacklist / RBL
  * SSL Certificate
  * Port Checker
  * HTTP Headers
  * HTTP/2 & HTTP/3
  * Ping
  * Traceroute

Email Tools

  * Email Health
  * SPF Checker
  * DKIM Checker
  * DMARC Checker
  * MTA-STS
  * BIMI Checker
  * Header Analyzer
  * SPF Generator
  * DMARC Generator

About

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and email admins.