Free tools
Free email tools
Four small tools for the questions that come up when mail goes wrong. They are free and need no account.
@
Email address check
Test one address: format, domain, mailbox and risk. A few free checks without an account.
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5xx
Bounce code library
Look up a code such as 550 5.1.1 and see what to do about it.
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MX
MX record lookup
See the servers that receive a domain's email, in priority order.
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SPF
SPF, DKIM and DMARC check
Audit the records that prove your mail is genuine and read what to fix.
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⚠
Disposable domain check
Find out whether a domain is a known throwaway service.
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How these tools work
- Each one answers a single question quickly, with nothing to install.
- They read public DNS records and server answers. No message is ever sent to the people you check.
Are they really free?
Yes. The domain tools and the bounce code library need no account.
Do you keep what I type?
The domain tools do not store the domains you enter. Results are cached briefly to keep them fast.
Where should I start?
If a message bounced, start with the bounce code library. If mail goes to spam, start with the SPF, DKIM and DMARC check.
Start with free credits
Create an account, check your first addresses and see the report. No card needed.
Create free account