MailTester Ninja for Python

Official client for the MailTester Ninja email verification API. Check in real time whether an email address is valid and deliverable: each address is checked against the recipient's mail server, and nothing is stored.

• No dependencies (standard library only), typed, Python 3.9+
• Free to try: no signup with key="free", or a free API token for 50 checks a day

pip install mailtester-ninja

Quickstart

from mailtester_ninja import MailTester

mt = MailTester()  # reads MAILTESTER_KEY, falls back to "free"

result = mt.verify("info@apple.com")
print(result.code, result.message)  # ok Accepted

Reading the verdict

Branch on code, show message to people.

A catch-all domain is never reported as valid. Shortcuts: result.is_valid, result.is_invalid, result.is_uncertain, and mt.is_deliverable(email).

Verify a list

verify_many checks one address at a time and paces the calls for you: 30 seconds apart on the free tier, 1 second with a paid key (override with delay). Errors are reported per address, the loop keeps going.

for email, result, error in mt.verify_many(["info@apple.com", "someone@example.com"]):
    if error:
        print(email, "no verdict:", error.message)
    else:
        print(email, result.code, result.message)

Errors

An error is never a verdict: do not drop an address because of it.

Keys and limits

Options: MailTester(key=None, base_url=..., timeout=60.0). The key defaults to the MAILTESTER_KEY environment variable, then to free.

Links

• API documentation and OpenAPI 3.1 specification
• Integrations: n8n, Zapier, Make, Clay, Google Sheets
• Code examples for other languages
• JavaScript and TypeScript client

License

MIT