Email Validator API

Email Validator API

The Email Validator API provides comprehensive email address validation with advanced features including deliverability checks, domain analysis, and security assessments. Improve your data quality by validating email addresses in real-time with detailed insights.

Key Features

• Real-time validation - Instant email address verification
• Deliverability assessment - Check if emails can receive messages
• Domain analysis - MX record validation and domain verification
• Security checks - SPF, DMARC, and DKIM record analysis
• Quality scoring - 0-100 quality score for each email
• Role-based detection - Identify generic role emails (admin@, support@)
• Disposable email detection - Filter out temporary email services
• Free provider identification - Detect Gmail, Yahoo, and other free providers
• Risk assessment - Low, medium, high risk categorization

Base URL

API Information

• API Version: v1
• Request Methods: GET, POST (Form Data), POST (JSON)
• Response Format: JSON

Authentication

All API requests require authentication using your Core Nexis client credentials. The API uses a simple but secure authentication system with client ID and API key validation.

Required Credentials

You need your Core Nexis API credentials to access this service:

Authentication Methods

Include your credentials in every request using one of these methods:

URL Parameters (GET Request)

[email protected]&client_id=YOUR_CLIENT_ID&api_key=YOUR_API_KEY

Form Data (POST Request)

Content-Type: application/x-www-form-urlencoded
[email protected]&client_id=YOUR_CLIENT_ID&api_key=YOUR_API_KEY

JSON Body (POST Request)

{
    "email": "[email protected]",
    "client_id": "YOUR_CLIENT_ID",
    "api_key": "YOUR_API_KEY"
}

Rate Limits & Pricing

API usage is subject to rate limits based on your subscription plan. All plans include comprehensive email validation features with different usage allowances and request rates.

Rate Limit Details

• Per Minute Limit: 5-10 requests depending on your plan
• Monthly Limit: 500-5,000 successful requests per month
• Rate Reset: Rate limits reset automatically
• Overage: Additional requests are blocked until reset

Endpoints

{
    "success": true,
    "input": "[email protected]",
    "normalized": "[email protected]",
    "is_deliverable": true,
    "is_role_based": false,
    "quality_score": 85,
    "risk_level": "low",
    "email_type": "corporate",
    "domain": "example.com",
    "mx_records": [
        {
            "host": "mx1.example.com",
            "priority": 10
        },
        {
            "host": "mx2.example.com",
            "priority": 20
        }
    ],
    "is_disposable": false,
    "is_free": false,
    "spf": "v=spf1 include:_spf.example.com ~all",
    "dmarc": "v=DMARC1; p=quarantine;",
    "dkim_selectors": ["default", "google"]
}

Response Fields

The API returns detailed information about each validated email address. Here's a comprehensive guide to understanding each field in the response.

Core Response Fields

Classification Fields

Technical Fields

Usage Examples

Here are comprehensive examples showing different ways to use the Email Validator API with all supported request methods.

1. GET Request

curl -X GET "https://api.corenexis.com/email/validator/v1/[email protected]&client_id=YOUR_CLIENT_ID&api_key=YOUR_API_KEY"

2. POST with Form Data

curl -X POST "https://api.corenexis.com/email/validator/v1/" \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "[email protected]&client_id=YOUR_CLIENT_ID&api_key=YOUR_API_KEY"

3. POST with JSON

curl -X POST "https://api.corenexis.com/email/validator/v1/" \
  -H "Content-Type: application/json" \
  -d '{
    "email": "[email protected]",
    "client_id": "YOUR_CLIENT_ID",
    "api_key": "YOUR_API_KEY"
  }'

4. Validate Corporate Email

curl -X POST "https://api.corenexis.com/email/validator/v1/" \
  -H "Content-Type: application/json" \
  -d '{
    "email": "[email protected]",
    "client_id": "YOUR_CLIENT_ID",
    "api_key": "YOUR_API_KEY"
  }'

5. Validate Free Email Provider

curl -X POST "https://api.corenexis.com/email/validator/v1/" \
  -H "Content-Type: application/json" \
  -d '{
    "email": "[email protected]",
    "client_id": "YOUR_CLIENT_ID",
    "api_key": "YOUR_API_KEY"
  }'

6. Validate Role-Based Email

curl -X POST "https://api.corenexis.com/email/validator/v1/" \
  -H "Content-Type: application/json" \
  -d '{
    "email": "[email protected]",
    "client_id": "YOUR_CLIENT_ID",
    "api_key": "YOUR_API_KEY"
  }'

Error Handling

The API uses standard HTTP status codes and provides detailed error messages for troubleshooting.

HTTP Status Codes

Common Error Responses

Invalid Client ID (404)

{
    "success": false,
    "error": {
        "code": 404,
        "message": "Invalid client ID"
    }
}

Invalid API Key (401)

{
    "success": false,
    "error": {
        "code": 401,
        "message": "API key invalid"
    }
}

Account Suspended (403)

{
    "success": false,
    "error": {
        "code": 403,
        "message": "Your account is suspended. Contact support."
    }
}

Account Expired (403)

{
    "success": false,
    "error": {
        "code": 403,
        "message": "Your account has been expired at 2025-12-31 18:20. Contact support."
    }
}

API Not Activated (403)

{
    "success": false,
    "error": {
        "code": 403,
        "message": "Email Validator is not activated in your plan"
    }
}

Rate Limit Exceeded (429)

{
    "success": false,
    "error": {
        "code": 429,
        "message": "Rate limit exceeded. Try again in 45 seconds.",
        "retry_after": 45
    }
}

Monthly Limit Exceeded (429)

{
    "success": false,
    "error": {
        "code": 429,
        "message": "Monthly limit exceeded. Please upgrade your plan or try on 2025-09-15"
    }
}

Missing Parameters (400)

{
    "success": false,
    "error": {
        "code": 400,
        "message": "Missing required parameters: email, client_id, api_key"
    }
}

Server Error (500)

{
    "success": false,
    "error": {
        "code": 500,
        "message": "Internal server error"
    }
}

Best Practices

Follow these best practices to get the most out of the Email Validator API and ensure optimal performance and data quality.

Implementation Guidelines

• Handle Rate Limits: Implement retry logic with exponential backoff for 429 responses
• Monitor Quality Scores: Set minimum quality thresholds based on your use case (typically 60-70)
• Check Disposable Emails: Filter out disposable emails for better data quality and engagement
• Validate Before Storage: Always validate emails before storing in your database
• Regular Cleanup: Periodically re-validate stored email addresses to maintain data quality

Quality Threshold Recommendations

Error Handling Best Practices

• Check Success Field: Always check the success field before processing results
• Handle Authentication Errors: Implement proper error handling for 401, 403, and 404 responses
• Respect Rate Limits: Use the retry_after field in 429 responses for backoff timing
• Log Errors: Keep detailed logs for debugging and monitoring purposes
• Fallback Strategy: Have a fallback validation method for when the API is unavailable

Data Usage Recommendations

Getting Started

Step 1: Sign Up for Core Nexis Account

Visit Core Nexis API Platform to create an account and get your:

• client_id - Your unique client identifier
• api_key - Your API key (starts with cn_)

Step 2: Choose Your Plan

Select a plan that matches your validation volume needs:

• Basic: 500 validations/month - Perfect for testing and small applications
• Starter: 2,500 validations/month - Ideal for growing businesses
• Pro: 5,000 validations/month - For established applications with higher volume
• Custom: Enterprise features and unlimited validations

Step 3: Start Validating

Use the examples provided in this documentation to start validating email addresses immediately.

Getting Help

Request API Access

To get your API credentials and activate the Email Validator API, please provide:

• Your intended use case for email validation
• Expected monthly validation volume
• Integration timeline and requirements
• Preferred subscription plan (Basic, Starter, Pro, or Custom)

What Makes Our Email Validator Special