REST API · JSON · free plan

Email Validation API

Check any email address from your own code. One GET request returns the syntax, MX, SMTP mailbox, disposable, role and free-provider checks, a deliverability state with its reason and a quality score. Whole lists go through the bulk endpoint, up to 100,000 addresses per job.

Get your free API key Read the docs

100 free requests a month
No credit card
Checks run in Germany

curl -H "apikey: YOUR-API-KEY" "https://api.emailvalidation.io/v1/info?email=anna@example.com"

Try the live API

Send a request, see the real response

Type an address and it goes to the same API your code will call. The JSON on the right is replaced with the response you get back.

Validate an email address

No signup

Each request runs these checks:

format_valid
mx_found
smtp_check
disposable
role
free

GET /v1/info

curl "https://api.emailvalidation.io/v1/info?email=support@emailvalidation.io" \
  -H "apikey: YOUR-API-KEY"

const res = await fetch(
  "https://api.emailvalidation.io/v1/info?email=" + encodeURIComponent(email),
  { headers: { apikey: process.env.EMAILVALIDATION_KEY } }
);
const { state, did_you_mean } = await res.json();
if (state === "undeliverable") // ask the user to fix the address

import os, requests

r = requests.get(
    "https://api.emailvalidation.io/v1/info",
    params={"email": email},
    headers={"apikey": os.environ["EMAILVALIDATION_KEY"]},
    timeout=10,
)
state = r.json()["state"]  # deliverable | risky | undeliverable | unknown

$ch = curl_init("https://api.emailvalidation.io/v1/info?email=" . urlencode($email));
curl_setopt($ch, CURLOPT_HTTPHEADER, ["apikey: YOUR-API-KEY"]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$result = json_decode(curl_exec($ch), true);

200 · GET /v1/info?email=support@emailvalidation.io

{
  "email": "support@emailvalidation.io",
  "user": "support",
  "tag": "",
  "domain": "emailvalidation.io",
  "format_valid": true,
  "mx_found": true,
  "smtp_check": true,
  "catch_all": null,
  "role": true,
  "disposable": false,
  "free": false,
  "score": 0.64,
  "state": "deliverable",
  "reason": "valid_mailbox",
  "did_you_mean": ""
}

From API key to first result in three steps

No SDK needed: any language that can send an HTTPS request can call the API.

Step
Create a free account
Sign up and copy your API key from the dashboard. The free plan includes 100 requests a month, at up to 10 requests a minute.
```
apikey: YOUR-API-KEY
```
Step
Call GET /v1/info
Pass the address as email and your key in the apikey header. The header is better than the query parameter, which can end up in access logs.
```
GET /v1/info?email=anna@example.com
```
Step
Act on the state
Branch on state and log reason: accept deliverable addresses, ask for a correction when an address is undeliverable, and decide case by case for risky and unknown ones.
```
"state": "deliverable"
```

Endpoints

Seven endpoints, one base URL

Every call goes to https://api.emailvalidation.io and returns JSON. Authenticate with your API key in the apikey header or the apikey query parameter.

One key, header or querySend the key as a header to keep it out of URLs and logs. Medium and Large plans can create more than one key.
Catch-all on requestAdd catch_all=1 to /v1/info or catch_all to a bulk job to test whether the domain accepts every address. Available from the Small plan.
Also an MCP serverAI agents reach the same checks at https://api.emailvalidation.io/mcp. Set up the MCP server.

API documentation OpenAPI (YAML)

GET/v1/infoValidate one address. Parameters: email, catch_all (1 or 0).
POST/v1/bulkStart a bulk job from a JSON array or a CSV or TXT file, up to 100,000 addresses.
GET/v1/bulkList your bulk jobs, newest first.
GET/v1/bulk/{job_id}Status, counts and progress of one job.
GET/v1/bulk/{job_id}/resultsDownload the results as JSON or CSV.
DELETE/v1/bulk/{job_id}Delete a job together with its list and results.
GET/v1/statusYour monthly quota: total, used and remaining. Free to call.

GET /v1/info

What the response tells you

Every response has the same 15 fields, so your code never has to guess which keys exist.

Field	Type	Meaning
`email`	string	The address that was checked.
`user`	string	The local part before the @.
`tag`	string	The tag part of the address, if it has one.
`domain`	string	The domain part after the @.
`format_valid`	boolean	Whether the address follows the email syntax rules.
`mx_found`	boolean	Whether the domain has MX records, the usual sign that it can receive email.
`smtp_check`	boolean	Whether the receiving mail server accepted the mailbox in the SMTP check.
`catch_all`	boolean \| null	Whether the domain accepts mail for every address. `null` unless you send `catch_all=1`.
`role`	boolean	A role address such as support@ or postmaster@.
`disposable`	boolean	An address at a disposable email service.
`free`	boolean	An address at a free email provider such as Gmail or Yahoo.
`score`	number	Quality score from 0 (bad) to 1 (good).
`state`	string	`deliverable`, `undeliverable`, `risky` or `unknown`.
`reason`	string	Why the address got its state, see the table below.
`did_you_mean`	string	A suggested correction for a likely domain typo, for example gmail.com for gmial.com. A suggestion only: it does not change the other fields.

Four states, eleven reasons

Branch on the state, keep the reason for your logs and support team.

deliverable

The mailbox exists. Accept the address.

valid_mailbox: A valid mailbox that can receive email.

risky

Accepted, but delivery or engagement is doubtful. Accept with care or ask again.

low_deliverability: A person is unlikely to read the email.
low_quality: Several people appear to use the address.

undeliverable

Mail will bounce. Block it or ask for a correction.

invalid_format: The address format is invalid.
invalid_mx: MX records are missing or invalid.
invalid_smtp: The mail server did not respond correctly.
invalid_mailbox: The mail server refused the address.

unknown

The server could not be asked. Retry later.

no_connect: No connection to the mail server.
timeout: The SMTP connection timed out.
unavailable_smtp: The server did not allow verification.
unexpected_error: An unexpected error occurred.

Full definitions in the /v1/info documentation.

Bulk email verification API

A whole list in one request

POST a JSON array or upload a CSV or TXT file with up to 100,000 addresses (25 MB). The job runs in the background: poll its status or let us call your webhook, then download the results.

Only unique, valid addresses are billedDuplicates (ignoring case and surrounding spaces) and empty or malformed rows are free, and a job that needs more than your remaining quota is refused before anything is charged.
Refunds for checks we could not finishAddresses left unknown because of a timeout on our side are refunded when the job completes; a failed job is refunded in full.
Signed webhookOne POST when the job completes or fails, signed with HMAC-SHA256, with up to six delivery attempts. It carries the job, never the addresses.

queuedAccepted, quota charged
processingChecked per mail server
completedResults ready for 30 days
failedFully refunded

POST /v1/bulk

curl -X POST "https://api.emailvalidation.io/v1/bulk" \
  -H "apikey: YOUR-API-KEY" \
  -F "file=@contacts.csv" \
  -F "email_column=email" \
  -F "webhook_url=https://example.com/hooks/emailvalidation"

201 · job created

{
  "job_id": "629954218123464704",
  "status": "queued",
  "counts": {
    "total": 5,
    "unique": 3,
    "duplicates": 1,
    "invalid": 1,
    …
  },
  "quota": { "charged": 3, "refunded": 0 },
  …
}

Results your way

JSON with a row number, the input and all 15 result fields per address
CSV: your original columns plus 15 emailvalidation_* columns
Cells starting with = + - or @ are escaped, so the CSV is safe to open in a spreadsheet
Download as often as you like until the job expires, or delete it right away

Bulk API docs No code? Clean a list in the app

Errors and limits

Predictable errors, clear limits

Every error has an HTTP status and a code, so your integration can tell a bad request from a full quota.

You only pay for successful checksValidation errors and errors on our side do not count against your quota. Status checks, job lists, downloads and deletions are free.
Rate limits in the headersThe free plan allows 10 requests a minute. Responses carry X-RateLimit-Remaining-Quota-Month, and X-Cost shows what a call counted.

Status	Meaning
200	Success.
201	Bulk job created.
401	No API key, or the key is invalid.
403	Key not allowed, or `plan_upgrade_required` for a feature your plan does not include.
404	Endpoint or job not found, or results no longer available.
409	`job_not_completed`: results requested before the job finished.
422	Validation error; the `errors` object names the field.
429	Rate limit or monthly quota exceeded.
500	Internal error on our side. Contact support.

Rate limit and quota headers

Header	Meaning
`X-RateLimit-Limit-Quota-Month`	Your monthly quota.
`X-RateLimit-Remaining-Quota-Month`	Requests left this month.
`X-RateLimit-Limit-Quota-Minute`	Requests allowed per minute, on plans with a minute limit such as the free plan (10).
`X-RateLimit-Remaining-Quota-Minute`	Requests left in the current minute.
`X-Cost`	What the call counted against your quota: 1 for a validation, 0 for sandbox requests; for a bulk job, the number of unique valid addresses.
`X-RateLimit-Remaining-Overage-Month`	Overage left, when overage is enabled and the monthly quota is used up (with `X-RateLimit-Limit-Overage-Month`).

Official SDKs and integrations

Install a client library or call the REST API directly.

JavaScript

npm install @everapi/emailvalidation-js --save

Python

pip install emailvalidationio

PHP

composer require everapi/emailvalidation-php

Official SDKs are also listed for Ruby, Go, C#, R, Rust and Perl.

MCP server

Let Claude, Cursor and other AI agents validate addresses and run bulk jobs.

MCP setup

Zapier

Validate new contacts from forms, CRMs and spreadsheets without code.

Zapier integration

Step-by-step guides

Validate email addresses in JavaScript, Python and PHP, with a regex check first.

JavaScript guide

Where teams call the API

Check an address at the moment it enters your system, before it costs you a bounce.

Signup forms

Catch typos and throwaway inboxes before the account exists, and suggest the right domain.

Checkout

Make sure order confirmations and invoices reach the buyer.

CRM imports

Keep invalid and role addresses out of your contact database.

Email marketing

Clean lists before a campaign to protect your sender reputation.

API pricing

The same plans as the app: one request validates one address.

Free

$0/month

100 email validations

Start for free

Small

$9.99/month

5,000 email validations

≈ $0.0020 per validation

Choose Small

MediumMost popular

$34.99/month

25,000 email validations

≈ $0.0014 per validation

Choose Medium

Large

$94.99/month

100,000 email validations

≈ $0.00095 per validation

Choose Large

Cancel any time · Two months free on yearly plans · All prices excl. VAT · Compare all plans

Email validation API FAQ

Short answers to what developers ask before they integrate.

Is the email validation API free?

Yes, to start. The free plan includes 100 requests a month at up to 10 requests a minute, with no credit card. Paid plans start at $9.99 a month for 5,000 validations.

How does the API check an address without sending an email?

It checks the syntax, looks up the domain's MX records and asks the receiving mail server over SMTP whether it would accept the mailbox. The conversation ends before any message is sent.

What does a catch-all result mean?

Some domains accept mail for every address, so the mailbox check cannot confirm one person. Send catch_all=1 (Small plan or higher) and the catch_all field tells you whether the domain is catch-all; without it the field is null.

Can I validate a whole list through the API?

Yes. POST /v1/bulk takes a JSON array or a CSV or TXT file with up to 100,000 addresses. Only unique, valid addresses are billed, and you get the results as JSON or as your CSV with the result columns added.

Which programming languages can I use?

Any language that can send an HTTPS request. There are official SDKs for JavaScript, Python and PHP, and SDKs are also listed for Ruby, Go, C#, R, Rust and Perl.

Do failed requests count against my quota?

No. Only successful calls count. Validation errors and errors on our side are not charged, and checks we could not finish in a bulk job are refunded.

Is an email verification API the same as an email validation API?

Yes. Email validation API, email verification API and email checker API are names for the same thing: an API that tells you whether an address is valid and will receive mail. This one checks the syntax, the domain and its MX records and the mailbox over SMTP, and flags disposable, role and free-provider addresses.

What happens when I reach my monthly quota?

Once any grace or overage quota is used up too, further requests return 429 until the quota resets at the start of your next billing month, or until you upgrade. The X-RateLimit-Remaining-Quota-Month header shows how many requests you have left, so your code can see it coming.

Is the API GDPR compliant?

We process your data in line with the GDPR. The API and every email check run on our own servers in Germany. Requests reach them through Cloudflare, which also stores uploaded lists. Our privacy policy names our main service providers.

Start validating emails for free

100 free checks every month. No credit card required. Upgrade when you need more.