Email Verification API:
Validate Emails in Real-Time
Integrate our real-time email verification API (also called an email validation API) into signup forms, checkout pages, and applications. Verify any email address with a single HTTP GET/POST request and get a detailed JSON/XML response in under one second on average. 10 free verifications daily, credits never expire.
GET|POST https://api.bulkemailchecker.com/
?apiKey=YOUR_API_KEY
&email=user@company.com
// Response: 200 OK (347ms)
{
"status": "passed",
"event": "mailbox_exists",
"isDisposable": false,
"creditsRemaining": 9850
}
Benefits of Real-Time Email Verification
Every invalid email that enters your database costs money and damages your sender reputation. Real-time email verification stops bad data at the point of entry, before it causes problems. Validate emails the instant a user types them, not weeks later in a batch job.
- Block Fake Signups InstantlyReject disposable, invalid, and mistyped emails before they enter your database
- Protect Checkout ConversionsEnsure order confirmations and receipts reach real inboxes
- Capture Quality Leads OnlyVerify every lead at the form level so your sales team contacts real people
- Keep Sender Reputation CleanPrevent bounces from ever happening by validating before you send
- Reduce Fraud and AbuseDetect disposable emails, role accounts, and gibberish addresses used by bots
- Works With Any StackSimple REST API with JSON/XML responses, compatible with every programming language
Signup Forms
Verify emails as users type. Show instant feedback and prevent fake accounts from ever being created.
Checkout Pages
Validate customer emails at purchase so order confirmations and shipping updates always arrive.
Lead Capture
Ensure every lead form submission contains a real, deliverable email address your team can contact.
CRM Data Entry
Validate emails at the point of entry into your CRM to maintain a clean, accurate contact database.
How the Email Verification API Works
Four steps from API request to verified result. The entire process takes less than one second.
Make an API Request
Send a simple HTTP GET/POST request to our API endpoint with your API key and the email address you want to verify. No SDKs or libraries required.
SMTP Handshake
Our server performs a real-time SMTP handshake with the destination mail server to confirm whether the specific mailbox exists, without sending any email.
Get JSON/XML Response
Receive a detailed JSON or XML response with the verification status, event code, intelligence flags (disposable, role, gibberish), and MX enrichment data.
Act on the Results
Use the response data to accept valid emails, reject invalid ones, prompt users to fix typos, or flag suspicious addresses for manual review.
API Response Example
Every verification returns a detailed JSON or XML response with the status, event, intelligence flags, and free MX enrichment data.
"status": "passed",
"event": "mailbox_exists",
"details": "The address provided passed all tests.",
"email": "example@gmail.com",
"emailSuggested": "",
"mailbox": "example",
"domain": "gmail.com",
"isComplainer": false,
"isDisposable": false,
"isFreeService": true,
"isGibberish": false,
"isOffensive": false,
"isRoleAccount": false,
"timestampUTC": "2026-01-22T04:52:08Z",
"execution": "0.03",
"creditsRemaining": 9850,
"hourlyQuotaRemaining": 2498,
"mxEnrichment": {
"mxIp": "142.250.102.27",
"mxHostname": "alt4.gmail-smtp-in.l.google.com",
"mxCity": "",
"mxPostalCode": "",
"mxState": "Texas",
"mxStateISOCode": "TX",
"mxCountry": "United States",
"mxCountryISOCode": "US",
"mxContinent": "North America",
"mxContinentISOCode": "NA",
"mxTimezone": "America/Chicago",
"mxLatitude": "32.7797",
"mxLongitude": "-96.8022",
"mxIsp": "Google Servers",
"mxIspOrganization": "Google Servers",
"mxAsn": 15169,
"mxAsnOrganization": "GOOGLE"
}
}
Key Features of Our Email Verification API
Everything you need to verify emails in real-time, built into a single API endpoint.
Sub-Second Response Times
Median response time of 300-800ms. Fast enough to validate emails inline on signup forms and checkout pages without any noticeable delay to the user.
99.7% Verification Accuracy
Real-time SMTP handshake with the destination mail server for every request. No stale cached databases. Live verification ensures the mailbox actually exists right now.
Disposable Email Blocking
Continuously updated database of thousands of disposable email providers including 10MinuteMail, Guerrilla Mail, and Mailinator. Block fake signups instantly.
Typo Correction Suggestions
Detects common domain misspellings like gnail.com, yaho.com, and hotmal.com. Returns suggested corrections so users can fix their email before submitting.
MX Enrichment Data Included Free
Every verification response includes the mail server IP, hostname, and geographic country at no additional cost. Useful for lead enrichment and fraud detection.
Works with Any Programming Language
Standard RESTful HTTP endpoint returning JSON or XML. Compatible with PHP, Python, Node.js, Ruby, Java, C#, Go, Swift, and any language that can make HTTP requests.
Code Examples for the Email Verification API
Integrate our email validation API in minutes. Here are ready-to-use examples in the most popular languages.
// Real-time email verification with PHP
$apiKey = 'YOUR_API_KEY';
$email = 'user@company.com';
$url = "https://api.bulkemailchecker.com/"
. "?apiKey=" . $apiKey
. "&email=" . urlencode($email);
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_TIMEOUT, 30);
$response = curl_exec($ch);
curl_close($ch);
$result = json_decode($response, true);
if ($result['status'] === 'passed') {
// Email is valid - proceed
echo "Valid email address.";
} else {
// Email is invalid - reject or prompt
echo "Invalid: " . $result['details'];
}
?>
import requests
api_key = "YOUR_API_KEY"
email = "user@company.com"
response = requests.get(
"https://api.bulkemailchecker.com/",
params={
"apiKey": api_key,
"email": email
}
)
result = response.json()
if result["status"] == "passed":
print("Valid email address.")
else:
print(f"Invalid: {result['details']}")
const apiKey = 'YOUR_API_KEY';
const email = 'user@company.com';
const url = new URL('https://api.bulkemailchecker.com/');
url.searchParams.set('apiKey', apiKey);
url.searchParams.set('email', email);
const response = await fetch(url);
const result = await response.json();
if (result.status === 'passed') {
console.log('Valid email address.');
} else {
console.log(`Invalid: ${result.details}`);
}
curl "https://api.bulkemailchecker.com/?apiKey=YOUR_API_KEY&email=user@company.com"
# With URL encoding and formatted output
curl -s "https://api.bulkemailchecker.com/" \
-G \
-d "apiKey=YOUR_API_KEY" \
--data-urlencode "email=user@company.com" \
| python3 -m json.tool
require 'net/http'
require 'json'
require 'uri'
api_key = 'YOUR_API_KEY'
email = 'user@company.com'
uri = URI('https://api.bulkemailchecker.com/')
uri.query = URI.encode_www_form(
'apiKey' => api_key,
'email' => email
)
response = Net::HTTP.get(uri)
result = JSON.parse(response)
if result['status'] == 'passed'
puts "Valid email address."
else
puts "Invalid: #{result['details']}"
end
package main
import (
"encoding/json"
"fmt"
"io"
"net/http"
"net/url"
)
func main() {
apiKey := "YOUR_API_KEY"
email := "user@company.com"
params := url.Values{}
params.Set("apiKey", apiKey)
params.Set("email", email)
resp, _ := http.Get(
"https://api.bulkemailchecker.com/?" + params.Encode(),
)
defer resp.Body.Close()
body, _ := io.ReadAll(resp.Body)
var result map[string]interface{}
json.Unmarshal(body, &result)
if result["status"] == "passed" {
fmt.Println("Valid email address.")
} else {
fmt.Printf("Invalid: %s\n", result["details"])
}
}
import java.net.*;
import java.io.*;
import org.json.*;
public class EmailVerifier {
public static void main(String[] args) throws Exception {
String apiKey = "YOUR_API_KEY";
String email = "user@company.com";
String endpoint = "https://api.bulkemailchecker.com/"
+ "?apiKey=" + URLEncoder.encode(apiKey, "UTF-8")
+ "&email=" + URLEncoder.encode(email, "UTF-8");
HttpURLConnection conn =
(HttpURLConnection) new URL(endpoint).openConnection();
conn.setRequestMethod("GET");
BufferedReader reader = new BufferedReader(
new InputStreamReader(conn.getInputStream())
);
StringBuilder sb = new StringBuilder();
String line;
while ((line = reader.readLine()) != null)
sb.append(line);
reader.close();
JSONObject result = new JSONObject(sb.toString());
if (result.getString("status").equals("passed")) {
System.out.println("Valid email address.");
} else {
System.out.println("Invalid: " + result.getString("details"));
}
}
}
using System.Net.Http;
using System.Text.Json;
var apiKey = "YOUR_API_KEY";
var email = "user@company.com";
var client = new HttpClient();
var url = $"https://api.bulkemailchecker.com/"
+ $"?apiKey={apiKey}&email={Uri.EscapeDataString(email)}";
var response = await client.GetStringAsync(url);
var result = JsonDocument.Parse(response).RootElement;
if (result.GetProperty("status").GetString() == "passed")
{
Console.WriteLine("Valid email address.");
}
else
{
var details = result.GetProperty("details").GetString();
Console.WriteLine($"Invalid: {details}");
}
Real-Time Email Verification API Use Cases
Wherever your application collects an email address, our API can verify it in real-time.
Signup Form Validation
Verify emails as users register. Block disposable addresses, catch typos, and ensure every new account has a real, deliverable email. Reduce fake signups by up to 95% and improve onboarding email deliverability.
Checkout Page Validation
Validate customer emails at checkout to guarantee order confirmations, receipts, and shipping updates reach real inboxes. Reduce support tickets from customers who never received their order email.
Lead Capture Forms
Ensure every lead captured through landing pages, gated content, and contact forms contains a valid email. Your sales team only contacts real people, improving connection rates and pipeline quality.
CRM Data Entry
Integrate the API into your CRM workflow to verify emails at the point of entry. Maintain a clean, accurate contact database and prevent bad data from contaminating your marketing and sales systems.
Email Verification API Pricing
Pay-as-you-go credits that never expire. No monthly fees, no contracts. Use credits for API verifications or bulk file uploads.
How Our Email Verification API Compares
We own our verification infrastructure and pass the savings directly to you.
| Feature | Bulk Email Checker | ZeroBounce | NeverBounce |
|---|---|---|---|
| Cost per 10,000 Verifications | $9.95 | $65 - $75 | $50 - $80 |
| Accuracy Rate | 99.7% | 99% | 97% |
| Average Response Time | 300-800ms | 1-3s | 1-5s |
| Credits Expire? | Never Expire | Monthly Limits | Monthly Limits |
| Monthly Fees | None (Pay-as-you-go) | Required | Required |
| Free MX Enrichment | Included | Extra cost | Not available |
| Unlimited API Option | From $250/mo | Not available | Not available |
| Unknown Results Billing | Free (zero credits) | Charged | Charged |
| Free Re-verification | Blacklisted emails | Not available | Not available |
Trusted by 8,500+ Organizations Worldwide
Developers and product teams at companies of all sizes rely on our email verification API.
"Integrated the API into our signup form in less than an hour. It instantly stopped the spam bots and fake signups we were dealing with daily."
"We tested 5 different email verification APIs. Bulk Email Checker had the best accuracy, fastest response times, and the pricing is unbeatable."
"The disposable email detection alone saved us thousands in wasted marketing spend. The API catches throwaway addresses that other services miss."
Enterprise-Grade API Security
Your data is protected by military-grade encryption and industry-leading compliance certifications.
Zero Data Retention
Email addresses submitted via API are verified in real-time and never stored on our servers. No logs, no caching, no data lingering.
API Key Authentication
Every API request is authenticated and encrypted over HTTPS. API keys can be rotated at any time from your dashboard.
99.99% Uptime SLA
Redundant infrastructure across multiple data centers with automatic failover ensures your integration never goes down.
Real-Time Email Verification API FAQ
Everything developers and product teams need to know about integrating our email verification API.
What is a real-time email verification API?
A real-time email verification API is a RESTful web service that validates an email address instantly at the point of entry. You send an HTTP GET or POST request with an email address, and the API performs SMTP handshake verification, disposable detection, syntax validation, and more. It returns a JSON or XML response with the full verification result in under one second.
How fast is the email verification API?
Our email verification API delivers sub-second response times for most requests. The median response time is 300-800 milliseconds depending on the destination mail server. This is fast enough to validate emails inline on forms without any noticeable delay.
What programming languages are supported?
The API is a standard RESTful HTTP endpoint that returns JSON or XML, so it works with any language that can make HTTP requests. This includes PHP, Python, Node.js, JavaScript, Ruby, Java, C#, Go, Rust, Swift, and more. See our API documentation for code examples.
How accurate is the email validation API?
We deliver 99.7% accuracy through real-time SMTP handshake verification. Unlike services relying on stale cached databases, we connect directly to the destination mail server for every single verification request to confirm whether the mailbox actually exists.
How much does the API cost?
API verifications use pay-as-you-go credits starting at $2.95 for 1,000 verifications. Volume pricing scales to $3,299.95 for 25 million verifications. Credits never expire and there are no monthly fees. For unlimited volume, see our Unlimited Email Verification API with flat monthly pricing plans.
What data does the API response include?
The JSON or XML response includes the verification status (passed, failed, unknown), a detailed event code, a human-readable description, and intelligence flags for disposable email, free service, role account, and gibberish detection. Free MX enrichment data (IP, hostname, country) is also included with every response.
Can the API detect disposable emails?
Yes. Every verification checks the email against a continuously updated database of thousands of disposable providers including 10MinuteMail, Guerrilla Mail, Mailinator, and more. The isDisposable flag in the response tells you instantly if the address is temporary.
Does the API provide typo correction?
Yes. The API detects common domain misspellings such as gnail.com, yaho.com, and hotmal.com. When a typo is detected, a suggested correction is returned so you can prompt the user to fix their email before it enters your database.
What is MX enrichment data?
MX enrichment is additional intelligence about the email's mail server included free with every verification. It provides the MX server IP address, hostname, and geographic country. Useful for lead enrichment, fraud detection, and understanding where your users' emails are hosted.
Do I get charged for unknown results?
No. You are only charged for Passed (valid) and Failed (invalid) results. Unknown results including catch-all domains, greylisting, and inconclusive checks consume zero credits. Previously blacklisted addresses also re-verify for free.
How do I authenticate with the API?
Include your API key as a query parameter in the request URL. Your API key is generated when you create a free account and can be found in your dashboard. All requests are encrypted with TLS 1.3. No complex OAuth flows or token management required.
What is the difference between real-time API and bulk verification?
Real-time API verifies individual emails instantly via HTTP request, ideal for forms and applications. Bulk verification processes large CSV/TXT files with thousands to millions of emails. Both use the same 99.7% accurate SMTP verification engine and the same pay-as-you-go credits.
What is SMTP verification and how does it work?
SMTP (Simple Mail Transfer Protocol) verification is the process of connecting to a mail server and asking it whether a specific mailbox exists, without actually sending an email. Our API initiates an SMTP handshake with the destination server: it connects, identifies itself, and requests delivery to the target address. The server responds with either a confirmation (250 OK) or a rejection (550 User Not Found). We then disconnect before any message is sent. This provides the most accurate way to determine if an email address is real and active.
Can I use the email verification API to validate emails on signup forms?
Yes, this is one of the most common use cases. You make an API call when a user enters their email on your signup form, checkout page, or lead capture form. The API responds in under one second with a pass/fail result, allowing you to reject invalid addresses before they enter your database. This prevents fake signups, reduces bounce rates, improves deliverability, and ensures you only pay to market to real people. See our API documentation for ready-to-use code examples.
What are the API rate limits?
The Real-Time Email Verification API is designed for transactional email verification in forms and allows up to 5 concurrent connections. For higher concurrency needs, we recommend our Unlimited Email Verification API which supports up to 50 concurrent requests with dedicated processing threads.
Is the email verification API GDPR compliant?
Yes. Our email verification API is fully GDPR compliant. Email addresses submitted for verification are processed in real-time, used solely for verification purposes, and are not stored, sold, or shared with third parties. All API traffic is encrypted with TLS 1.3. We hold SOC 2 Type II, ISO 27001, CCPA, and HIPAA certifications.
What happens when the destination mail server is down or unreachable?
When a destination mail server is temporarily unavailable, our API returns an "Unknown" status rather than a false negative. We implement automatic retries with configurable timeouts (up to 60 seconds) to account for temporary outages and greylisting. You are never charged credits for Unknown results. If accuracy for a specific address is critical, you can re-verify it later when the server is back online.
Does the API support batch or async verification requests?
The real-time API is designed for single-email verification with instant responses. For batch processing of large lists, use our Bulk Email Verifier which accepts CSV and TXT file uploads. If you need high-throughput programmatic batch verification, our Unlimited Email Verification API provides dedicated concurrent threads that can process thousands of verifications per minute in parallel.
Start Verifying Emails in Real-Time Today
Create a free account, get your API key, and integrate our email verification API in under 10 minutes.