---
id: mailchecker
version: "6.0.21"
license: unclear
license_treatment: permissive
maintenance: active
---

# mailchecker — Cross-language temporary email detection library. Stop users from signing up with temporary email addresses.

License: permissive · Maintenance: active · Downloads: 588.4K/mo

## What it is and what it does

MailChecker is a cross-language email validation library that performs two checks: format validation (using standard email regex patterns) and temporary email detection (by checking against a curated database of over 55,000 known disposable email domains). It helps prevent sign-ups and communications with throwaway email services like Yopmail and similar providers.

The package is designed for developers who need to filter out temporary email addresses during user registration or contact workflows. It has no runtime dependencies, installs quickly, and provides a simple API: call `MailChecker.is_valid()` with an email string and receive a boolean result. The underlying domain list is maintained by the project maintainers and can be extended by contributors.

Use it for:

- Block temporary email addresses during user registration to ensure valid contact information.
- Filter out disposable emails from mailing lists before sending campaigns to reduce bounce rates.
- Validate email format and reject known spam-box domains in contact forms.
- Pre-screen user signups to avoid wasted communication attempts with non-functional addresses.
- Integrate email validation into data import pipelines to catch bad addresses early.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Validates email addresses against format rules and checks whether they belong to temporary/throwaway email services using a database of over 55,000 known disposable domains.

Yes. The package solves a real problem with zero dependencies, permissive licensing, active maintenance, and a straightforward API. Use it when you need to reject temporary email addresses during signup or contact workflows. The only caveat is verifying that the throwaway domain database stays current for your use case.

## Install

pip install mailchecker
uv add mailchecker
poetry add mailchecker

## Installing mailchecker

Before you install: Low friction installation with no runtime dependencies. The package is actively maintained with a recent release (26 days ago) and has accumulated 1901 repository stars, indicating stable, long-term support.

License in practice: Licensed under MIT (permissive), so you can use it freely in commercial and open-source projects without restriction or attribution requirement.

Quickstart:

pip install mailchecker

from MailChecker import MailChecker

if not MailChecker.is_valid('bla@example.com'):
    print("Invalid email")

Requires Python 3.6 or later.

Verify before relying:

- Whether the throwaway domain database is updated automatically or requires manual maintenance.
- Performance characteristics when validating large batches of emails.
- Exact regex used for format validation and how it compares to RFC 5322 compliance.

## Package facts

- License: not declared (permissive)
- Python support: supports_current
- Install friction: low
- Maintenance: active
- Downloads: 588.4K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

email validation, temporary email detection, disposable email checker, email format validator, spam email blocker, throwaway email detection, email verification library, email-validation, user-input-validation

[View on SkillFed](https://skillfed.io/packages/mailchecker) · [View on PyPI](https://pypi.org/project/mailchecker/)