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Email Verification API for Developers
Simple REST API for real-time email validation. Integrate in minutes with comprehensive documentation and code examples in multiple languages.
Simple Integration
Get Started in Minutes
Copy and paste one of these examples to validate your first email address.
cURL
curl -X POST https://api.campaignkit.cc/v1/email/validate \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"emails": ["test@example.com"]}'JavaScript (Node.js)
const response = await fetch('https://api.campaignkit.cc/v1/email/validate', {
method: 'POST',
headers: {
'Authorization': 'Bearer YOUR_API_KEY',
'Content-Type': 'application/json'
},
body: JSON.stringify({ emails: ['test@example.com'] })
});
const data = await response.json();
console.log(`Classifier: ${data.results[0].result.classifier}`);
console.log(`Score: ${data.results[0].result.score}/10`);Python
import requests
response = requests.post(
'https://api.campaignkit.cc/v1/email/validate',
headers={'Authorization': 'Bearer YOUR_API_KEY'},
json={'emails': ['test@example.com']}
)
data = response.json()
result = data['results'][0]['result']
print(f"Classifier: {result['classifier']}")
print(f"Score: {result['score']}/10")Quick Start
Integrate in 3 Simple Steps
From signup to production in under 5 minutes with our developer-friendly REST API.
- 1Get Your API Key
Sign up for free and generate your API key from the dashboard in seconds. No credit card required to start.
- 2Make Your First Request
Use our REST API to validate emails with a simple POST request. Get instant results with detailed validation data.
- 3Integrate & Scale
Add validation to your forms, CRM, or workflows. Process single emails or batch validate up to 100 at once.
Developer Experience
Built for Developers
Everything you need for a smooth integration experience.
- Simple REST API
- Clean, intuitive RESTful API design with JSON requests and responses. No SDK required.
- Comprehensive Documentation
- Detailed API docs with code examples in multiple languages and step-by-step guides.
- Batch Validation
- Validate up to 100 email addresses in a single API request for efficient bulk processing.
- Webhook Support
- Receive real-time notifications when validation jobs complete with HMAC signature verification.
- Detailed Response Data
- Rich validation results with syntax, MX, mailbox checks, scores, classifiers, and detailed flags.
- Transparent Rate Limits
- Clear rate limits based on your plan with helpful error messages and retry guidance.
- Multi-Language Support
- Works with any language that can make HTTP requests. Examples provided for JavaScript, Python, PHP.
- Secure Authentication
- Simple Bearer token authentication with API key management in your dashboard.
Use Cases
When to Use Email Validation API
Common scenarios where email validation adds value to your applications.
Form Validation
Validate email addresses in real-time as users submit forms to prevent invalid data from entering your system.
- User registration
- Newsletter signups
- Contact forms
- Lead capture
List Cleaning
Bulk validate your existing email lists to improve deliverability and reduce bounce rates.
- Customer databases
- Marketing lists
- CRM data cleanup
- User database maintenance
CRM Integration
Automatically validate new contacts as they're added to your CRM or customer database.
- Salesforce integration
- HubSpot workflows
- Custom CRM systems
- Data enrichment pipelines
E-commerce Protection
Verify customer emails during checkout to reduce fraud and ensure order confirmations are delivered.
- Order validation
- Account creation
- Fraud prevention
- Customer verification
Developer FAQ
Common questions about integrating the API. Can't find what you need? Check our full documentation or contact support.
- How do I authenticate API requests?
- Use Bearer token authentication by including your API key in the Authorization header: "Authorization: Bearer YOUR_API_KEY". You can generate API keys in your dashboard under API Settings.
- What are the rate limits?
- Rate limits vary by plan: Free (10 req/min), Starter (60 req/min), Professional (300 req/min), Enterprise (custom). Each request can validate up to 100 emails, so you can process 1,000-30,000 emails per minute depending on your plan.
- Can I validate emails in bulk?
- Yes. You can send up to 100 email addresses in a single API request for efficient batch processing. For larger lists, make multiple requests or use webhooks to get notified when validation jobs complete.
- How much does each validation cost?
- Each unique email validation consumes one credit. Duplicate emails in the same request are deduplicated automatically. The API response includes a "creditsUsed" field showing exactly how many credits were consumed. Pricing starts at $0.008 per validation with volume discounts available.
- Do you have webhooks?
- Yes. You can create webhook subscriptions to receive POST notifications when validation jobs complete. Webhooks include HMAC-SHA256 signatures for security verification. See our webhook documentation for setup instructions.
- What language SDKs are available?
- Our REST API works with any language that can make HTTP requests. We provide code examples for JavaScript (Node.js), Python, and PHP in our documentation. No official SDKs are required—the API is simple enough to integrate directly.
- How fast is the API?
- Average response time is under 500ms for single email validation. Batch requests (up to 100 emails) typically complete in 1-3 seconds. Our API has 99.9% uptime and is backed by global CDN infrastructure.
- What data is returned in the response?
- Each validation returns: email address, contextId, syntax check (pass/fail), MX record check, mailbox verification, deliverability score (0-10), classifier (valid/risky/invalid), description flags (disposable, role_email, catchall, etc.), and SMTP response. This gives you complete control over how to handle each email.