Check if an e-mail address has a Yahoo account

The Yahoo check answers whether an e-mail address has a Yahoo Mail account. It covers yahoo.com, Yahoo's country domains and the older ymail.com and rocketmail.com addresses. It runs in bulk jobs and returns registered: true, false or null (unknown) for each address, with the time we checked. Nothing is sent to the address and no mailbox is read.

#What does the Yahoo check tell you?

It tells you whether Yahoo has an account at the exact address you send. Yahoo Mail is one of the oldest free web mail services, and over the years it has handed out addresses under several domains. Customer databases therefore contain @yahoo.com, country versions like @yahoo.co.uk, @yahoo.fr or @yahoo.de, and the alternative @ymail.com and @rocketmail.com domains.

• registered: true: a Yahoo account exists at this address.
• registered: false: a conclusive "no account".
• registered: null: no conclusive answer. status and reason say why, and you are not charged.

Many Yahoo addresses were created years ago and never used again. Yahoo's own terms allow it to close accounts that stay inactive, so an address that worked in an old export may no longer exist. The check answers that question for today, and checked_at records when.

#Who uses it, and why?

Yahoo addresses are common among long-standing consumers, which makes them important in older data and in some regional markets.

• Hygiene for older customer records. Before a service or account notice to existing customers, a batch run finds Yahoo addresses that no longer have an account. Updating them through another channel beats watching the message bounce.
• Deliverability. Large mailbox providers track how often a sender hits non-existent addresses. Removing dead Yahoo addresses protects delivery of receipts, alerts and password resets.
• Sign-up review. A nightly job over new sign-ups flags Yahoo addresses that never existed. That is a typical trait of scripted registrations. See OTP and sign-up fraud.

For a real-time answer while the user is on the form, use the mailbox check. To cover a whole list across providers, combine Yahoo with the Gmail and Outlook checks in one job.

#What do you get back?

Each address becomes a row with kind: "email" and one entry per check in checks.

CSV and NDJSON downloads keep your original row order and add yahoo.email.status, yahoo.email.registered and yahoo.email.billed columns.

#How is it billed?

You pay the bulk price per address with a conclusive answer. You're not charged for inconclusive results (unknown, unsupported country, timeout, invalid, duplicate). Run the free POST /v1/jobs/estimate first to see valid, duplicate and cached counts and the maximum cost, then pass that figure as max_cost. See pricing.

Repeat checks of the same address inside the freshness window can come from your account's cache. Cache hits are free.

#What are the limits?

The Yahoo check is bulk only. POST /v1/lookup refuses it with 403 service_disabled ("The check 'yahoo.email' is available in bulk jobs only (POST /v1/jobs)."). A job takes up to 50,000 numbers and e-mails, as JSON or as a CSV upload with an email column.

• Up to 20 checks per request. Identifiers × applicable checks are capped at 100,000 per job.
• Requests that look like sequential number ranges or generated e-mail lists are rejected. Twenty or more addresses in one request on one domain whose local parts differ only by digits or separators are refused with suspected_enumeration. Live keys are also limited to 50 addresses of one such pattern per account per UTC day.
• Addresses are trimmed and lowercased, never rewritten.
• The daily cap counts e-mail addresses like numbers (see GET /v1/limits).

#How do I use it responsibly?

Check addresses from your own customers, users and leads, where you have a lawful reason to process them. We never open mailboxes and never send e-mail to the address. The answer is yes, no or unknown, and never includes personal details.

An existing account does not mean consent. Don't use the check to prepare unsolicited mailings, and don't test address variations to see whether someone has a Yahoo account. The acceptable use policy forbids both. People can object through the opt-out form. Suppressed addresses are skipped and never charged.

#Example request

Test keys return fixed answers for test.mobilevalidate.com addresses (see test mode).

curl https://api.mobilevalidate.com/v1/jobs \
  -H "Authorization: Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym" \
  -H "Content-Type: application/json" \
  -d '{"emails":["[email protected]","[email protected]","[email protected]"],"checks":["yahoo"]}'

// npm install mobilevalidate · Node.js 20+ · save as check.mjs and run: node check.mjs
import { MobileValidate } from "mobilevalidate";

// Omit apiKey to read MOBILEVALIDATE_API_KEY from the environment.
const mv = new MobileValidate({ apiKey: "mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym" });
const { data, error } = await mv.jobs.create({
  emails: [
    "[email protected]",
    "[email protected]",
    "[email protected]",
  ],
  checks: ["yahoo"],
});
if (error) console.error(error.code, error.message);
else console.dir(data, { depth: null });

// Node.js 18+, Deno, Bun or the browser console (ES module: save as .mjs or use "type": "module").
const res = await fetch("https://api.mobilevalidate.com/v1/jobs", {
  method: "POST",
  headers: {
    Authorization: "Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    emails: [
      "[email protected]",
      "[email protected]",
      "[email protected]",
    ],
    checks: ["yahoo"],
  }),
});
console.log(res.status, res.headers.get("x-request-id"));
console.dir(await res.json(), { depth: null });

# pip install mobilevalidate-sdk
from mobilevalidate import MobileValidate

# Omit api_key to read MOBILEVALIDATE_API_KEY from the environment.
mv = MobileValidate(api_key="mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym")
result = mv.jobs.create(
    emails=[
        "[email protected]",
        "[email protected]",
        "[email protected]",
    ],
    checks=["yahoo"],
)
print(result)

<?php
$ch = curl_init('https://api.mobilevalidate.com/v1/jobs');
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'Authorization: Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym',
        'Content-Type: application/json',
    ],
    CURLOPT_POSTFIELDS => json_encode([
        'emails' => [
            '[email protected]',
            '[email protected]',
            '[email protected]',
        ],
        'checks' => ['yahoo'],
    ]),
]);
$response = curl_exec($ch);
echo curl_getinfo($ch, CURLINFO_RESPONSE_CODE), PHP_EOL, $response, PHP_EOL;

package main

import (
	"fmt"
	"io"
	"net/http"
	"strings"
)

func main() {
	body := strings.NewReader(`{"emails":["[email protected]","[email protected]","[email protected]"],"checks":["yahoo"]}`)
	req, err := http.NewRequest("POST", "https://api.mobilevalidate.com/v1/jobs", body)
	if err != nil {
		panic(err)
	}
	req.Header.Set("Authorization", "Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym")
	req.Header.Set("Content-Type", "application/json")
	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()
	out, _ := io.ReadAll(res.Body)
	fmt.Println(res.Status, string(out))
}

require "net/http"
require "json"

uri = URI("https://api.mobilevalidate.com/v1/jobs")
req = Net::HTTP::Post.new(uri)
req["Authorization"] = "Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym"
req["Content-Type"] = "application/json"
req.body = JSON.generate({
  "emails" => [
    "[email protected]",
    "[email protected]",
    "[email protected]"
  ],
  "checks" => ["yahoo"]
})

res = Net::HTTP.start(uri.host, uri.port, use_ssl: true) { |http| http.request(req) }
puts res.code, res.body

Response of GET /v1/jobs/{id}/results (excerpt, test mode: the first item of data):

{
  "kind": "email",
  "input": "re•••@test.mobilevalidate.com",
  "email": "[email protected]",
  "email_status": "valid",
  "e164": null,
  "country": null,
  "checks": {
    "yahoo.email": {
      "service": "yahoo.email",
      "status": "completed",
      "registered": true,
      "attributes": null,
      "confidence": "high",
      "confidence_score": 0.99,
      "checked_at": "2026-09-25T14:25:31.802Z",
      "cached": false,
      "age_seconds": 0,
      "billed": false,
      "reason": null,
      "poll_after_ms": null
    }
  },
  "test": true
}