DNS Doctor

Free tools · no signup

DNS & email tools

Run a check right here, or open a tool. Each card shows what it hands back, from example data; the same checks the full scan runs, never an AI guess.

Scan a whole domain →

Email authentication · 9 tools

Example resultReal message
Email test →Send one real email and see how it authenticated, scored out of 10.
7.5/10
Example resultSPF · RFC 7208
SPF lookup counter →Count an SPF record's DNS lookups against the 10-lookup limit.
10/ 10 lookups
Example resultDMARC · RFC 9989
DMARC record checker →Validate every tag in a DMARC record, and see the next safe policy step.
p=nonep=quarantinep=reject
Example resultDKIM · RFC 6376
DKIM checker →Read any DKIM selector's published key — strength and revocation.
1024-bit RSA keyWeak
Example resultDMARC · RFC 9989
DMARC record generator →Build a ready-to-publish DMARC record, RFC-validated in code.
v=DMARC1; p=quarantine; np=reject; rua=mailto:dmarc-reports@example.com
Example resultSPF + DMARC · trace
DMARC visualizer →Watch a receiving mail server evaluate your domain, step by step.
27 steps, from the SPF fetch to the verdict
Example resultDMARC · RFC 9989
DMARC report viewer →Read one aggregate report as a table of sending sources and alignment.
96%aligned of 203 messages
Example resultBIMI · logo readiness
BIMI checker →Check whether a domain is eligible to show its logo in the inbox, mailbox by mailbox.
Logo can show in 3 of 5 mailboxesChecks pass
Example resultBIMI · SVG Tiny PS
BIMI SVG converter →Convert a square SVG logo to the SVG Tiny PS profile BIMI requires.
357 bytes of SVG Tiny PSConverted

DNS · 4 tools

Example resultDNS · live read
DNS record checker →Read a record from its own nameservers beside two caching resolvers.
Caches catch up within 53 sUpdating
Example resultDNS · 6 locations
DNS propagation checker →Read one name from six locations on four continents at once.
6 of 6 locations answered, 5 different answersPartial
Example resultRegistration · RDAP
WHOIS lookup →Read a domain's registrar, expiry date, locks and nameservers.
Expires 16 Feb 2027Transfer locked
Example resultReverse DNS · round trip
Reverse DNS checker →Check a mail server IP's reverse name resolves back to the same address.
8.8.8.8 → dns.googleConfirmed