Free DNS & email checks
Is your domain
set up right?
Check the servers that run your website and email: nameservers, mail records, spam blocklists. Every result is explained in plain English, and you get a link you can send to whoever looks after your website.
Try one
Every check
Each one answers a single question. Type the command in the box above, or open the page directly: dns.rehab/mx/example.com.
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DNS check
dns:example.comAre the servers that answer for this domain healthy and set up correctly?
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MX lookup
mx:example.comWhich servers receive email for this domain?
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A lookup
a:example.comWhich IPv4 address does this name point to?
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AAAA lookup
aaaa:example.comWhich IPv6 address does this name point to?
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TXT lookup
txt:example.comWhat text records are published at this name?
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Reverse (PTR) lookup
ptr:8.8.8.8What name does this IP address claim, and does it point back?
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SPF check
spf:example.comWhich servers are allowed to send email as this domain?
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DMARC check
dmarc:example.comWhat should receivers do with email that fails your checks?
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DKIM check
dkim:example.com:selectorIs this domain's email signed with a key receivers can check?
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Blacklist check
blacklist:example.com or 203.0.113.7Is this address on the blocklists mail servers use?
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DNS propagation
propagation:example.comDo public DNS resolvers around the world see the same answer?
Commands, if you like typing
The box understands type:target, the same shorthand as the classic "SuperTool". A bare domain runs the DNS check; a bare IP address runs the blacklist check.
| Command | What it does |
|---|---|
| dns:example.com | Are the servers that answer for this domain healthy and set up correctly? |
| mx:example.com | Which servers receive email for this domain? |
| a:example.com | Which IPv4 address does this name point to? |
| aaaa:example.com | Which IPv6 address does this name point to? |
| txt:example.com | What text records are published at this name? |
| ptr:8.8.8.8 | What name does this IP address claim, and does it point back? |
| spf:example.com | Which servers are allowed to send email as this domain? |
| dmarc:example.com | What should receivers do with email that fails your checks? |
| dkim:example.com:selector | Is this domain's email signed with a key receivers can check? |
| blacklist:example.com or 203.0.113.7 | Is this address on the blocklists mail servers use? |
propagation:example.comadd :mx, :txt… to compare other record types |
Do public DNS resolvers around the world see the same answer? |
The full audit
Everything above in one pass, plus MTA-STS, TLS reporting, BIMI and your AI-crawler policy — scored out of 10, with what to fix first. It takes up to a minute.