Free tool
Catch-All Email Checker
Find out whether a domain accepts mail for every address, and how to handle the addresses on it. No email is sent.
What the catch-all checker does
A catch-all checker tests whether a domain's mail server accepts mail for any address, real or not. On a catch-all domain a plain SMTP check says every address is valid, so lists full of them bounce. This tool identifies the domain's mail provider and how it treats unknown recipients. RocketVerifier then scores each catch-all address as send_safe, send_with_caution or avoid.
How it works
How the Catch-All Checker works
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Enter a domain
Type a domain, or paste an email address and we use its domain.
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Mail provider identified
We read the MX records and identify the provider or security gateway behind them.
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Catch-all behaviour
See how the server treats addresses that do not exist, and what that means for your list.
Reading your result
What the result means
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Not catch-all
Unknown addresses are rejected, so every address gets a definite deliverable or undeliverable verdict.
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Catch-all
Every address is accepted at SMTP. Use the per-address catch-all score to decide what to send to.
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Depends on configuration
Workspace, Microsoft 365, gateways and self-hosted servers can go either way. Full verification tests each domain live.
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No mail server
The domain has no MX records, so every address on it is undeliverable.
FAQ
Catch-all checker FAQ
What is a catch-all domain?
A domain whose mail server accepts mail for every address, whether a mailbox exists or not. A plain SMTP check says yes to every address on it, so you need more than an accept to know whether an address is real.
How do you detect a catch-all domain without sending email?
After the real address is accepted, RocketVerifier asks the same server, in the same SMTP session, about random addresses that cannot exist. If those are accepted too, the domain is catch-all. The session stops before DATA, so no email is sent.
Should I send to catch-all addresses?
Send to the ones that score well. RocketVerifier scores every catch-all address from 0 to 100 using the provider, how plausible the local part is and the domain's address pattern: 65 and above is send_safe, 35 to 64 send_with_caution, under 35 avoid.
Are Gmail and Outlook.com catch-all?
No. Consumer providers such as Gmail, Outlook.com, Yahoo and iCloud reject addresses that do not exist, so every address on them gets a definite answer.
Does catch-all detection cost extra?
No. Catch-all detection and the catch-all verdict are part of every verification, at 1 credit per address. Unknown results are never charged.
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Clean a list
A verdict for every catch-all address
Stop guessing on accept-all domains. Every catch-all address gets a 0 to 100 score and a clear send decision, included in every verification.
100 free credits · No card required · Credits never expire