--- title: "Free Email Verifier: Check an Address | Emvero" description: "Verify an email address with syntax, domain and recipient evidence. Confirm a new account for 100 full checks; no card or verification email needed." url: https://emvero.io/email-verification/ language: en updated: 2026-10-07 --- Free email verifier # Check whether an email address can receive mail Emvero checks the address format and the domain's mail setup, then asks the receiving mail server about the mailbox when possible. You get a status, a recommended action and the reasons behind them. Some addresses remain uncertain. Create an account and confirm your email to receive 1,000 credits: enough for 100 full checks or up to 500 domain checks. No card required. Start for free View pricing Full checks require an account · No email sent to the address you check Example check Same fields the API returns Risky person@mailinator.example A finding such as a catch-all domain, disposable-mail provider or a reported mailbox problem needs review. Read the reason codes and recommended action to decide how to handle the address. Recommended action: `allow` - No technical reason to reject the address was found. 1. 01 Syntax passed 2. 02 Domain passed 3. 03 Mail routing passed 4. 04 Mailbox probe passed `SMTP_RCPT_ACCEPTED` Recipient accepted `DISPOSABLE_DOMAIN` Disposable address provider Illustrative result for a fictional address at a disposable-mail provider. The server accepted the recipient, but the provider signal makes the status risky. No live check runs here; use your account to check an address. See the [privacy policy](https://emvero.io/privacy/) for how Emvero processes and retains the data used in a check. ## What an email verification checks A correctly formatted address is only the starting point. Emvero checks whether the domain exists and has a mail route before attempting a mailbox check. Later stages stop if an earlier one establishes a definite failure. 1. 01 Syntax Check the address format, including the part before `@`, the domain and length limits. This stage needs no network connection. 2. 02 Domain Look up the domain in DNS, the system that publishes domain records. A non-existent domain ends the check; a temporary lookup failure leaves the result uncertain. 3. 03 Mail routing Find the domain’s mail route. MX records name its mail servers. A domain may use a fallback route or publish a null MX record to declare that it accepts no mail. 4. 04 Mailbox probe At full depth, ask the receiving server about the mailbox when possible. The SMTP conversation stops before `DATA`, so no email is sent. 5. 05 Classification Combine the findings into a status and recommended action. Reason codes explain the evidence, including any limits that leave the address uncertain. If you only need to inspect the domain’s mail setup, use the free [email domain checker](https://emvero.io/email-domain-checker/). A working website does not mean the domain receives email, and a mail route does not establish that a particular mailbox exists. ## How the mailbox check works without sending email SMTP is the protocol mail servers use to receive email. When a destination permits a mailbox check, Emvero connects to its server and names the recipient. This simplified example shows a server accepting the recipient: ``` CONNECT mx.company.com:25 EHLO MAIL FROM RCPT TO 250 2.1.5 Recipient OK RSET QUIT ``` The conversation stops before `DATA`, the stage where a message would be submitted. No subject or body is sent. Acceptance is evidence about this exchange. The server may apply different rules when a real message arrives, so the reply does not guarantee delivery. A refusal can also reflect restrictions on the probe rather than a missing mailbox. Emvero does not automatically reject an address based on an SMTP refusal. ## What the result means A completed check has one of four statuses. Read its recommended action as well: an address marked `risky` may be allowed or require email confirmation, depending on the reason. Deliverable Action: `allow` The receiving server accepted the recipient, and the check found no signal that made the address risky. This supports mail acceptance, but does not guarantee delivery or prove who controls the mailbox. Risky Action: `allow_with_email_confirmation` / `allow` A specific finding needs review, such as a catch-all domain, a disposable-mail provider or a server reporting a mailbox problem. The recommendation depends on that finding. Read the reason codes to decide whether to allow the address or require email confirmation. Undeliverable Action: `reject` The check found a definite technical failure, such as invalid syntax, a non-existent domain or a domain that explicitly accepts no mail. Reject this address or ask the person to correct it. Unknown Action: `allow_with_email_confirmation` The available evidence could not settle the address. A timeout, a temporary restriction or an ambiguous server reply can cause this result. It does not establish that the address is invalid. Require email confirmation when mailbox control matters. A full check may first return `pending` while the mailbox check continues. Wait for the completed result before treating it as a final status. The result also includes `checks`, which records the individual findings, and `reason_codes`, which explain them. Invalid syntax, a non-existent domain or a null MX record can establish `undeliverable`. A null MX record is the domain’s explicit declaration that it accepts no mail. A timeout or ambiguous SMTP refusal leaves the result `unknown`. The `action` field recommends `allow`, `allow_with_email_confirmation` or `reject`. Use it together with the status and reasons. The guide to [interpreting a verification result](https://emvero.io/blog/reading-a-verification-result/) explains how to apply these fields in your workflow. ## When an address needs closer review **Catch-all servers accept names without confirming a mailbox** A server that accepts both the requested address and an invented recipient may be accepting every name at the domain. Its acceptance cannot tell you whether the requested mailbox exists. A [catch-all domain](https://emvero.io/glossary/catch-all-domain/) can produce a `risky` result because the individual mailbox remains uncertain. Other signals need different handling: - A disposable-mail provider may offer a working mailbox that is temporary. An accepted recipient at such a provider can be `risky` with an `allow` recommendation. The free [disposable email checker](https://emvero.io/disposable-email-checker/) identifies the provider; it does not test the mailbox. - A role account such as `support@` belongs to a function or team. That attribute alone does not make it `risky`; it can still be `deliverable`. - A suggested domain correction flags a possible typo. Let the person confirm a correction rather than changing the address automatically. Decide how these signals affect your own use of the address. If access depends on someone controlling the mailbox, send your own confirmation email and require them to act on it. Emvero’s check does not establish control or send that confirmation for you. ## Choose a full check or a domain check Both depths use the same account balance. Choose the depth per check, according to the evidence you need. | Full check | Domain check | | --- | --- | | At most 10 credits | 2 credits | | Checks syntax, domain and mail routing, and may gather SMTP recipient evidence | Stops after syntax, DNS and mail routing; no SMTP session | | Can establish new catch-all evidence where probing is allowed | Can report only an already-known catch-all state | | May first return `pending` | Cannot establish an individual mailbox | A full check may cost less if it stops early. It can also finish as `risky` or `unknown`: “full” describes the scope of the check, not a guarantee of a conclusive answer. Neither depth guarantees future delivery or inbox placement. ## Check addresses in your own workflow Use the account checker for individual addresses. For checks within your application or across a list, use the same verification service through the API. ### Check from your application Send an address from your server and use the returned status, action and reasons in your application. ### Check a list Make one API request per address and save each result alongside your record. You manage the list and output in your own system. ### Check during signup or checkout Check an address while the person can still correct it. Decide how your form should handle a pending or uncertain result. Questions ## Frequently asked. **How do I check whether an email address is valid?** Run a full check in your account. It checks the address format, domain and mail route, and may ask the receiving server about the mailbox. Read the status and recommended action alongside the reasons: a correctly formatted address can still have a missing domain or an uncertain mailbox. **Can an email verifier prove a mailbox exists?** A server accepting the recipient supports that conclusion, but some servers accept any name or postpone checking the mailbox until a message is sent. Emvero can return `risky` or `unknown` when the evidence is inconclusive. To establish that someone controls the address, send your own confirmation email and require them to act on it. **Can I verify an address without sending it a message?** Yes. A full check may contact the mail server, but it stops before `DATA`, the stage where a message would be submitted. No email is sent to the address being checked. Confirming your Emvero account requires a separate email sent to your own address. **Should I choose a full check or a domain check?** Choose a domain check for address format, domain and mail-routing evidence. It costs 2 credits and does not contact the mail server. Choose a full check when you also need evidence about the recipient or new catch-all behaviour. It costs at most 10 credits and can still return an uncertain result. Neither depth guarantees future delivery or inbox placement. **Is the full email verifier free?** A new account receives 1,000 credits after you confirm your email, with no card required. That covers 100 full checks or up to 500 domain checks. Full checks use your account balance; buy more credits when it runs out. This page shows an example; sign in to check your own address. ## Compared side by side ### SMTP verification vs. syntax validation Syntax validation checks the address format. SMTP verification adds the receiving server’s response about the recipient. Neither guarantees that a future message will arrive. ### Catch-all domain A domain that accepts arbitrary recipient names, so an accepted address may have no individual mailbox. Run a check ## Check your first address Create an account, confirm your email and open the checker. Your 1,000 starting credits cover 100 full checks or up to 500 domain checks. You can also use them through the API. No card required. Start for free View pricing