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Python Email Validator: Check 10,000 Emails in Under a Minute

#python #automation #productivity #beginners

Python Email Validator: Check 10,000 Emails in Under a Minute

Stop sending emails to dead addresses. This Python script validates email lists in bulk.

Install 

pip install dnspython
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The Script 

import re
import dns.resolver
from concurrent.futures import ThreadPoolExecutor

def validate_format(email):
    pattern = r'^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$'
    return bool(re.match(pattern, email))

def check_mx(domain):
    try:
        dns.resolver.resolve(domain, 'MX')
        return True
    except:
        return False

def validate(email):
    if not validate_format(email): return False, 'bad_format'
    domain = email.split('@')[1]
    if not check_mx(domain): return False, 'no_mx'
    return True, 'valid'

def batch_validate(emails, workers=50):
    with ThreadPoolExecutor(max_workers=workers) as ex:
        return list(ex.map(validate, emails))

emails = ['user@gmail.com', 'bad@fake12345.com', 'test@python.org']
results = batch_validate(emails)
for email, (valid, reason) in zip(emails, results):
    print(f'{email}: {valid} ({reason})')
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Scale to 10,000 Emails

With 100 workers, 10,000 emails takes under 60 seconds.

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