Frequently asked questions

A pay-as-you-go email validation service. You can check one address, upload a list of up to 1,000,000 rows (CSV, XLSX or TXT), or call the REST API. Each result says whether the address is deliverable, undeliverable, risky or unknown, with a reason and a recommended action. It is a commercial service run by Inbox Perfection LLC.

In practice, yes. Both describe checking that an address is well formed, that its domain can receive mail and, where the mail server allows it, that the mailbox exists. Some people use "validation" for the format check alone. On this site both words mean the full check.

A check looks at the syntax, the domain's DNS and MX records, and then asks the receiving mail server whether the mailbox exists. We also flag disposable, role and catch-all addresses. No email is sent to the address you check.

Credits come in one-time packs: 10,000 for $35 ($3.50 per 1,000), 25,000 for $49 ($1.96 per 1,000), 50,000 for $79 ($1.58 per 1,000) and 1,000,000 for $450 ($0.45 per 1,000). One credit checks one address. There is no subscription. Prices in USD, excluding tax. VAT or sales tax is added at checkout where applicable.

Every new account gets 500 free credits with no card needed. The email checker page also gives 5 free single checks a day without an account.

Each of your first 3 payments adds 15% extra credits. Buying the 10,000-credit pack gives you 11,500 credits, and buying 1,000,000 gives you 1,150,000. From your fourth payment on, you get the pack's standard amount. It applies to every payment method; a card can earn it on at most 3 payments across accounts.

Yes. Every credit expires 24 months after it was added to your account, whether it was free, bonus or purchased. We always spend the credits that expire soonest first.

No. Any result with the status unknown is free. That includes checks where the receiving mail server does not answer within 15 seconds. Requests that fail with an error, malformed addresses and test addresses are free too.

No. Credit purchases are final. Because unknown results and errors are never charged, you pay only for checks that return a definite result. This does not affect any statutory rights you may have.

A catch-all domain accepts mail for any address at that domain, real or not. No verifier can confirm a specific mailbox there without sending a message. We mark these results risky with the reason catch_all. Keep them in a separate segment, send to them carefully and watch your bounces.

Four: deliverable, undeliverable, risky and unknown. Every result also has a reason that explains why, such as no_mailbox, disposable or greylisted, and a recommended action: send, send with caution, remove or retry later.

Deliverable means the mailbox existed and accepted our check at that moment. A message can still bounce if the mailbox was closed later, if it is full, if the receiving server blocks your sending IP or domain, or if it limits how fast you send. The bounce code from your sending platform tells you which.

Up to 1,000,000 rows per file, in CSV, XLSX or TXT format. You can follow progress in your dashboard and download the results when the job finishes. You can also get a webhook call when it completes.

Uploaded lists and their result files are deleted automatically 30 days after upload. Checks you run in the dashboard stay in your history for 30 days. API checks are not stored. To answer repeat checks, we keep only the result of a completed check for 12 months, under a keyed hash of the address, never the address itself.

Accounts that have made a purchase can send up to 500 validation requests per second; before the first purchase the limit is 20 per second. Each check waits up to 15 seconds for the receiving mail server. If it takes longer, you get unknown and no credit is used.

The API is HTTPS and JSON, described by an OpenAPI 3.1 spec. There are official SDKs for JavaScript/TypeScript and Python, and the docs have code samples for curl, JavaScript, TypeScript, Python, PHP, Ruby, Go, Java, C# and Rust.

Yes. Our MCP server lets MCP-compatible AI clients validate addresses with your API key. It uses the same credits, limits and free-unknown rule as the API.

Yes. We call a URL you register when a bulk job finishes or when your credits run low. Each call is signed so you can verify it came from us.

With a 6-digit code sent to your email, with Google, or with a passkey. There are no passwords.

Email support@email-validation.org or use the help chat on our pages. Support is handled by an AI assistant that answers from our documentation and policies. It cannot see or change your account, credits or payments; you manage those in your dashboard. Privacy, abuse, legal and security requests sent to their own addresses are reviewed by a person.

No. We pass addresses only to the processors listed on our subprocessors page, under a data processing agreement, to perform the check.

The website and API run on the Cloudflare global network. Mailbox checks are processed in the United States. The privacy policy and the subprocessors page list who processes data and where.

No. There are only one-time credit packs, and you buy credits when you need them.

Yes. Call the validate endpoint from your server when the form is submitted, then act on the result: accept deliverable addresses, ask the person to fix undeliverable ones and likely typos, and accept risky and unknown results but flag them. Never put your API key in browser code.