DNS Tools

Query any DNS record type, test a domain's email security — SPF, DMARC and DKIM — and check mail-server spam blacklists.

DNS lookup

Email security check (SPF / DMARC / DKIM)

Checks whether a domain is protected against email spoofing. DKIM selector is optional — common ones: selector1 / selector2 (Microsoft 365), google (Google Workspace).

WHOIS lookup

Looks up a domain's registration details via RDAP (the modern, structured successor to WHOIS) — registrar, domain status, name servers, DNSSEC and key dates. Supports .au (.com.au, .net.au, .org.au, .edu.au, .id.au), .com, .net, .org and most other gTLDs. Registrant contact details are normally redacted for privacy.

Mail-server blacklist check (DNSBL)

Checks whether a mail server's IPv4 address is listed on the major spam blacklists — the first thing to rule out when a customer says "our emails are bouncing".

Record type cheat-sheet

A	Hostname → IPv4 address
AAAA	Hostname → IPv6 address
MX	Mail servers (lower priority wins)
NS	Authoritative name servers
TXT	Free text — SPF, verification keys
CNAME	Alias to another hostname
SOA	Zone authority + serial
CAA	Which CAs may issue certificates
SRV	Service location (port + host)
PTR	IP → hostname (reverse DNS)

Why SPF + DKIM + DMARC?

SPF lists the servers allowed to send mail for your domain. DKIM cryptographically signs each message. DMARC tells receivers what to do when both fail — and sends you reports. All three together stop most domain spoofing; any one alone leaves gaps. Aim for SPF ending in -all, a valid DKIM key, and DMARC at p=quarantine or p=reject.