The undeliverable status

Undeliverable1 credit per result · default action: Remove

Undeliverable means mail sent to this address will not arrive. It costs 1 credit (except malformed addresses, which we answer for free without a check) and the usual action is remove.

What to do

On a form: ask the person to correct the address. When did_you_mean is set, offer the suggestion ("Did you mean name@example.com?") rather than changing it silently.
On a list: remove the address or move it to a suppression list, so it is not imported again later.
mailbox_full: the mailbox exists but is turning away mail now. If the contact matters, you can re-check it in a few weeks; otherwise treat it as undeliverable.

Sending to undeliverable addresses produces hard bounces, which mailbox providers count against your sender reputation.

Reasons

Mailbox not found

no_mailbox: The domain receives mail, but this particular mailbox does not exist.

Recommended action: Remove. Remove the address from your list or ask for another one.
Credit: 1 credit when it comes from a completed check.
Test address: no_mailbox@sandbox.email-validation.org (free)

Example response

{
  "email": "no_mailbox@sandbox.email-validation.org",
  "status": "undeliverable",
  "reason": "no_mailbox",
  "action": "remove",
  "account": "no_mailbox",
  "domain": "sandbox.email-validation.org",
  "did_you_mean": null,
  "free_email": false,
  "role_account": null,
  "disposable": null,
  "catch_all_domain": null,
  "mx_found": true,
  "mx_record": "mx.sandbox.email-validation.org",
  "smtp_provider": "other",
  "domain_age_days": 3650,
  "processed_at": "2026-11-02T09:30:00.000Z",
  "credits_used": 0,
  "request_id": "req_7Hq2LmX9cV4bN8tR1zK6wD"
}

Domain does not receive mail

no_inbound_mail: The domain is set up to send mail only and turns away incoming messages.

Recommended action: Remove. Remove the address from your list or ask for another one.
Credit: 1 credit when it comes from a completed check.
Test address: no_inbound_mail@sandbox.email-validation.org (free)

Example response

{
  "email": "no_inbound_mail@sandbox.email-validation.org",
  "status": "undeliverable",
  "reason": "no_inbound_mail",
  "action": "remove",
  "account": "no_inbound_mail",
  "domain": "sandbox.email-validation.org",
  "did_you_mean": null,
  "free_email": false,
  "role_account": null,
  "disposable": null,
  "catch_all_domain": null,
  "mx_found": false,
  "mx_record": null,
  "smtp_provider": null,
  "domain_age_days": 3650,
  "processed_at": "2026-11-02T09:30:00.000Z",
  "credits_used": 0,
  "request_id": "req_7Hq2LmX9cV4bN8tR1zK6wD"
}

Not a valid address

invalid_syntax: The text is not a well-formed email address, so no mail server could ever accept it.

Recommended action: Remove. Remove the address from your list or ask for another one.
Credit: 1 credit when it comes from a completed check.
Test address: invalid_syntax@sandbox.email-validation.org (free)

Example response

{
  "email": "invalid_syntax@sandbox.email-validation.org",
  "status": "undeliverable",
  "reason": "invalid_syntax",
  "action": "remove",
  "account": "invalid_syntax",
  "domain": "sandbox.email-validation.org",
  "did_you_mean": null,
  "free_email": false,
  "role_account": null,
  "disposable": null,
  "catch_all_domain": null,
  "mx_found": false,
  "mx_record": null,
  "smtp_provider": null,
  "domain_age_days": 3650,
  "processed_at": "2026-11-02T09:30:00.000Z",
  "credits_used": 0,
  "request_id": "req_7Hq2LmX9cV4bN8tR1zK6wD"
}

Likely typo

likely_typo: The domain looks like a misspelling of a common mail provider, so check the suggested correction.

Recommended action: Remove. Remove the address from your list or ask for another one.
Credit: 1 credit when it comes from a completed check.
Test address: likely_typo@sandbox.email-validation.org (free)

Example response

{
  "email": "likely_typo@sandbox.email-validation.org",
  "status": "undeliverable",
  "reason": "likely_typo",
  "action": "remove",
  "account": "likely_typo",
  "domain": "sandbox.email-validation.org",
  "did_you_mean": "accepted@sandbox.email-validation.org",
  "free_email": false,
  "role_account": null,
  "disposable": null,
  "catch_all_domain": null,
  "mx_found": true,
  "mx_record": "mx.sandbox.email-validation.org",
  "smtp_provider": "other",
  "domain_age_days": 3650,
  "processed_at": "2026-11-02T09:30:00.000Z",
  "credits_used": 0,
  "request_id": "req_7Hq2LmX9cV4bN8tR1zK6wD"
}

Domain has no mail records

no_dns: The domain has no DNS records that tell senders where to deliver mail.

Recommended action: Remove. Remove the address from your list or ask for another one.
Credit: 1 credit when it comes from a completed check.
Test address: no_dns@sandbox.email-validation.org (free)

Example response

{
  "email": "no_dns@sandbox.email-validation.org",
  "status": "undeliverable",
  "reason": "no_dns",
  "action": "remove",
  "account": "no_dns",
  "domain": "sandbox.email-validation.org",
  "did_you_mean": null,
  "free_email": false,
  "role_account": null,
  "disposable": null,
  "catch_all_domain": null,
  "mx_found": false,
  "mx_record": null,
  "smtp_provider": null,
  "domain_age_days": 3650,
  "processed_at": "2026-11-02T09:30:00.000Z",
  "credits_used": 0,
  "request_id": "req_7Hq2LmX9cV4bN8tR1zK6wD"
}

Mailbox full

mailbox_full: The mailbox exists but is over its storage limit and is turning away new mail.

Recommended action: Remove. Remove the address from your list or ask for another one.
Credit: 1 credit when it comes from a completed check.
Test address: mailbox_full@sandbox.email-validation.org (free)

Example response

{
  "email": "mailbox_full@sandbox.email-validation.org",
  "status": "undeliverable",
  "reason": "mailbox_full",
  "action": "remove",
  "account": "mailbox_full",
  "domain": "sandbox.email-validation.org",
  "did_you_mean": null,
  "free_email": false,
  "role_account": null,
  "disposable": null,
  "catch_all_domain": null,
  "mx_found": true,
  "mx_record": "mx.sandbox.email-validation.org",
  "smtp_provider": "other",
  "domain_age_days": 3650,
  "processed_at": "2026-11-02T09:30:00.000Z",
  "credits_used": 0,
  "request_id": "req_7Hq2LmX9cV4bN8tR1zK6wD"
}

Mail server unreachable

unroutable: The domain points its mail to a server address that cannot be reached on the public internet.

Recommended action: Remove. Remove the address from your list or ask for another one.
Credit: 1 credit when it comes from a completed check.
Test address: unroutable@sandbox.email-validation.org (free)

Example response

{
  "email": "unroutable@sandbox.email-validation.org",
  "status": "undeliverable",
  "reason": "unroutable",
  "action": "remove",
  "account": "unroutable",
  "domain": "sandbox.email-validation.org",
  "did_you_mean": null,
  "free_email": false,
  "role_account": null,
  "disposable": null,
  "catch_all_domain": null,
  "mx_found": true,
  "mx_record": "mx.sandbox.email-validation.org",
  "smtp_provider": "other",
  "domain_age_days": 3650,
  "processed_at": "2026-11-02T09:30:00.000Z",
  "credits_used": 0,
  "request_id": "req_7Hq2LmX9cV4bN8tR1zK6wD"
}