Email

These tools help you confirm that your mail arrives and that nobody is spoofing your domain. They validate address format, check SPF, DKIM, and DMARC records and generate a DKIM record, and open DMARC aggregate reports — plus verify propagation across DNS servers worldwide, validate DNSSEC, MTA-STS, DANE/TLSA, and TLS-RPT, and analyse the headers of a received message.

Email Address Validator

Instantly check whether an email address matches a practical RFC 5322-style format, and verify whether its domain can actually receive mail (MX record lookup). Free tool for form validation and mailing list cleanup.

SPF/DKIM/DMARC Record Checker

Look up SPF, DMARC, and DKIM records for any domain in real time and diagnose your anti-spoofing email authentication setup.

DNS Record Type Reference Guide

A reference covering the DNS record types you need for running mail and websites — A, MX, TXT, SPF, DKIM, DMARC and more — with purpose, syntax examples, and gotchas for each.

DNS Propagation Checker (Free) - Check DNS Records Worldwide

Free tool to query a domain's DNS records against multiple public resolvers around the world (Google, Cloudflare, and more) at once, so you can instantly see whether a nameserver or record change has propagated globally.

DNSSEC Checker

Query a domain's DNSKEY record against multiple public DNS resolvers (Google, Cloudflare, and more) to check whether its DNSSEC signature chain validates correctly.

MTA-STS Policy Checker

Fetches a domain's _mta-sts TXT record and mta-sts.txt policy file to diagnose whether MTA-STS (mandatory TLS encryption for inbound mail) is configured correctly.

DANE/TLSA Record Checker

Query the TLSA records published by a domain's mail servers (MX hosts) against multiple public DNS resolvers to check whether DANE certificate pinning is configured.

TLS-RPT (SMTP TLS Reporting) Record Checker

Fetches a domain's _smtp._tls TXT record to diagnose whether the report destination (rua) for failed TLS connections is configured correctly per RFC 8460. Useful alongside MTA-STS/DANE.

DMARC Aggregate Report Viewer

Upload a DMARC aggregate report (XML, gzip, or ZIP) from your mail server to see SPF/DKIM authentication and policy results by source IP in a readable table. Parsing happens 100% in your browser — the file is never uploa...

DKIM DNS Record Generator

Enter a selector name and public key (PEM format) to generate the DNS TXT record for DKIM signing (v=DKIM1; k=rsa; p=...). Public keys longer than 255 characters are automatically split into BIND zone file format.

Email Header Analyzer

Paste the raw headers of a received email (Received:, Authentication-Results:, etc.) to see the delivery path broken down hop by hop, along with SPF/DKIM/DMARC results. Parsing runs 100% in your browser.