us-cert.gov email verification
Check whether an email address at the us-cert.gov domain is valid, deliverable and safe to send. Free single checks, no signup required.
5 of 5 free checks left today — no signup required.
Syntax check
Confirms the address follows the correct format for us-cert.gov.
MX & domain validation
Verifies that us-cert.gov has active mail exchange records.
SMTP mailbox test
Checks the mailbox existence without sending an email.
How verification works for us-cert.gov addresses
us-cert.gov is not one of the large consumer webmail providers, so its mail is handled by whichever mail server its MX records point to — often Google Workspace, Microsoft 365, or a self-hosted server. That matters because acceptance rules, catch-all behaviour and greylisting are configured per domain rather than per provider.
A live check is the only reliable way to know the current state. VeriMailX resolves the MX records for us-cert.gov, connects to the receiving server and asks whether the mailbox exists, then reports the result together with disposable, role-based and syntax flags. No email is ever sent to the address.
Learn more in the email verification guide or browse the domain directory.
Frequently asked questions
How do I check if an email address at us-cert.gov is valid?
Enter the address in the verifier above. VeriMailX checks the syntax, resolves the MX records for us-cert.gov, opens an SMTP conversation with the receiving mail server and reports whether the mailbox accepts mail — without sending an email.
Is us-cert.gov a catch-all domain?
Catch-all configuration is set by whoever administers us-cert.gov, and it can change at any time. A live verification tells you whether the server accepted the specific address or accepts everything, which is why catch-all status is reported per check rather than stored as a fixed value.
Can I verify a bulk list of us-cert.gov addresses?
Yes. Upload a CSV of up to 50,000 rows per file, or call the API for real-time checks at signup. Results include deliverability status, disposable and role-based flags, and a confidence score for each address.
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Upload a CSV, connect via API or set up auto-revalidation for us-cert.gov and any other domain.
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