Getting started
Understanding results
Every result has a status, which tells you what to do, and a reason, which tells you why.
Statuses
| Status | Meaning | What to do |
|---|---|---|
| deliverable | The mail server accepted this exact mailbox and rejected a random one. | Send. |
| undeliverable | It will bounce: bad syntax, no such domain, or the server said the mailbox doesn't exist or is disabled. | Remove it. At signup, ask the user to fix it. |
| risky | Might be accepted, but unsafe: an accept-all domain, a disposable inbox, or a full mailbox. | Your call. Accept-all business addresses are often real. |
| unknown | We couldn't get a definite answer: greylisting, timeouts, or a provider that accepts everything (Yahoo, AOL). | Retry later, or treat as risky. |
Reasons
| Reason | Status | Notes |
|---|---|---|
accepted | deliverable | Mailbox confirmed. |
invalid_syntax | undeliverable | Not a valid address. |
domain_not_found | undeliverable | The domain doesn't exist. |
domain_accepts_no_mail | undeliverable | No MX records, or a null MX. |
mailbox_not_found | undeliverable | Server said the user doesn't exist. |
mailbox_disabled | undeliverable | Account disabled or suspended. |
accept_all | risky | Domain accepts every address, so we can't tell. |
disposable | risky | Throwaway inbox provider. |
mailbox_full | risky | Over quota; mail will bounce for now. |
temporary_failure | unknown | Greylisted or a temporary error. |
smtp_unreachable | unknown | Couldn't connect to any mail server. |
smtp_blocked | unknown | The server refused to talk to us. |
smtp_rejected | unknown | Rejected for a reason other than the mailbox. |
dns_failure | unknown | DNS lookup failed. |
unverifiable_provider | unknown | This provider never gives a usable answer (e.g. Yahoo), so we don't probe it. |
provider_paused | unknown | We're backing off this provider for a few minutes. |
timeout | unknown | The server took too long. |
sender_rejected | unknown | The server refused our checking address. Our problem, not yours. |
Other fields
| Field | Type | Description |
|---|---|---|
did_you_mean | string | Suggested fix for common domain typos (gmial.com → gmail.com). Worth showing at signup. |
disposable | boolean | Address is on a disposable-inbox domain. |
role_account | boolean | Role mailbox like info@, sales@ or support@. |
free_provider | boolean | Consumer provider like Gmail or Outlook. |
accept_all | boolean | null | Whether the domain accepts any address; null if not tested. |
mx_host | string | The mail server we spoke to. |
smtp | object | The mail server's reply: code, enhanced code and message. |
cached | boolean | Served from cache. Definite results are reused for 30 days, unknown for 1 hour. |
duration_ms | number | Time the check took. |
Flags are independent of status: an address can be deliverable and a role_account at the same time.