Mail tools

Free SPF, DMARC and DKIM checker. Enter a domain to test MX, SPF, DMARC policy and DKIM selectors, see if your mail can be spoofed, and get concrete fixes.

Free SPF checker. Validate a domain's SPF record, count the RFC 7208 DNS-lookup limit (max 10), and check the all-qualifier — with the exact fix.

Free SPF IP tester. Enter a domain and a sending IP to see the exact SPF result a receiving mail server would record — pass, fail, softfail, neutral or permerror — and the mechanism that matched.

Free DMARC checker. Look up a domain's DMARC record and read its policy (none/quarantine/reject), subdomain policy, percentage, alignment and report address.

Free BIMI checker. Look up a domain's BIMI record, its SVG logo and Verified Mark Certificate (VMC) — and what's needed to show your brand logo in inboxes.

Free DKIM checker. Look up a domain's DKIM public key by selector, see the key type and bit length (1024 vs 2048), and detect testing/revoked keys — with the fix.

Free MTA-STS checker. Validate the _mta-sts TXT record and the published policy file (mode, covered MX, max_age) so inbound SMTP requires TLS — with the exact fix.

Free TLS-RPT checker. Validate the _smtp._tls TXT record (RFC 8460) and its rua report destinations so you learn when senders fail TLS/MTA-STS — with the fix.

Free DANE checker. Look up TLSA records at _25._tcp.<mx> for every MX host (RFC 7672) so senders can pin TLS and refuse downgrade — with the exact fix.

Free DNSBL blacklist check plus a StopForumSpam spam score. Test an IPv4 or domain against 13 blacklists (Spamhaus ZEN, SpamCop, Barracuda, SORBS, PSBL and more) and see the IP's 0-100 spam confidence.

Free SMTP server test. Connect to a mail server (or a domain's MX), read its ESMTP capabilities, check STARTTLS, reverse DNS, and run a safe open-relay test — with fixes.

Free mail server (MX) health check. For every MX host of a domain it verifies forward-confirmed reverse DNS (FCrDNS / PTR match), STARTTLS with certificate validity and TLS version, and the SMTP banner — the things receivers judge before accepting your mail. Works for Microsoft 365 and Google Workspace too.

Free email bounce analyzer. Paste a non-delivery report (NDR) and get the SMTP reply + enhanced status code decoded — the real cause (auth, reputation, content, rate limit, bad recipient) and the exact fix.

Paste a raw email to check it for phishing signals (mismatched links, look-alike domains), content/spam risk, tracking pixels, and bulk-sender compliance — List-Unsubscribe and RFC 8058 one-click — with per-receiver guidance.

Free URL reputation checker. Test a link or domain against the Spamhaus DBL, SURBL and URIBL blocklists, follow its redirect chain, and detect shorteners — so spammy links don't sink your email.

Free DMARC report analyzer. Paste a DMARC aggregate (rua) XML report and see who's sending as your domain: pass/fail rates and the exact source IPs failing alignment — so you can safely reach p=reject.

Free generator for mail DNS records. Enter your domain and get a correct, copy-paste SPF, DMARC, DKIM, MTA-STS, TLS-RPT or BIMI record, the exact name to publish it at, and the rollout steps.