email_check.py
import requests
API_KEY = 'YOUR_API_KEY'
response = requests.get(
'https://api.api-ninjas.com/v1/validateemail',
params={'email': 'test@example.com'},
headers={'X-Api-Key': API_KEY},
)
print(response.json())Prerequisites
- Python 3.7+ installed
- The
requestslibrary (pip install requests) - A free API Ninjas API key
Step 1: Get your API key
Sign up at api-ninjas.com/register.
Step 2: Make the API request
email_check.py
import requests
API_KEY = 'YOUR_API_KEY'
response = requests.get(
'https://api.api-ninjas.com/v1/validateemail',
params={'email': 'test@example.com'},
headers={'X-Api-Key': API_KEY},
)
print(response.json())Step 3: Inspect the response
JSON
{
"email": "test@example.com",
"is_valid": true,
"is_disposable": false,
"mx_found": true,
"smtp_check": true
}Complete example with deliverability filter
A real validation flow rejects three things: bad syntax, domains without mail servers, and disposable addresses:
email_check.py
import os
import requests
API_KEY = os.environ['API_NINJAS_KEY']
URL = 'https://api.api-ninjas.com/v1/validateemail'
def validate_email(email: str) -> dict:
response = requests.get(
URL,
params={'email': email},
headers={'X-Api-Key': API_KEY},
timeout=10,
)
response.raise_for_status()
return response.json()
def is_safe_to_send(email: str) -> bool:
result = validate_email(email)
return (
result['is_valid']
and result.get('mx_found', False)
and not result.get('is_disposable', False)
)
if __name__ == '__main__':
for email in ['user@gmail.com', 'fake@notarealdomain.xyz', 'user@mailinator.com']:
ok = is_safe_to_send(email)
print(f"{'✓' if ok else '✗'} {email}")Validating emails in a sign-up form
A Flask endpoint that rejects invalid or disposable addresses:
app.py
from flask import Flask, request, jsonify
app = Flask(__name__)
@app.route('/signup', methods=['POST'])
def signup():
email = request.json.get('email', '')
result = validate_email(email)
if not result['is_valid']:
return jsonify({'error': 'Please enter a valid email address'}), 400
if not result.get('mx_found'):
return jsonify({'error': 'Email domain cannot receive mail'}), 400
if result.get('is_disposable'):
return jsonify({'error': 'Disposable email addresses are not allowed'}), 400
# Proceed with sign-up...
return jsonify({'ok': True})Bulk-validating a list of emails
Python
with open('emails.txt') as f:
emails = [line.strip() for line in f if line.strip()]
valid = []
invalid = []
for email in emails:
result = validate_email(email)
(valid if result['is_valid'] else invalid).append(email)
print(f"Valid: {len(valid)}")
print(f"Invalid: {len(invalid)}")For lists over a few thousand, throttle requests to stay under your plan's rate limit.
Related APIs
Pair email validation with Validate Phone, Disposable Email Checker, or MX Lookup for deeper contact-hygiene workflows.