How to update the disposable email domain list in MailChecker?

Edit the central list.txt file in the GitHub repository and submit a pull request; running 'npm run build' regenerates all language libraries from this list. Regular updates are community-dependent, so you may need to monitor for new releases.

MailChecker vs validator.js for email validation?

MailChecker adds disposable domain detection on top of basic format validation, while validator.js focuses solely on syntax and standards. Use MailChecker if blocking temporary emails is critical; otherwise, validator.js is lighter for format-only checks.

Can MailChecker verify if an email address actually exists?

No, MailChecker only validates format and checks against its disposable domain database; it does not perform real-time deliverability checks like sending confirmation emails or querying MX records.

How to add custom domains to the blacklist for my project?

You can fork the repository, append domains to list.txt, and rebuild the libraries locally. For production, consider maintaining a separate list or contributing to the main project to benefit the community.

Is MailChecker suitable for high-traffic websites or APIs?

Yes, but the in-memory domain set may add memory overhead. Validation calls are fast O(1) lookups, so performance impact is minimal after initial load, but test in your environment for scalability.

How to integrate MailChecker with a Django project?

Use the django-indisposable package mentioned in the README, which provides a Django validator wrapper. Alternatively, import the Python library directly and call MailChecker.is_valid() in your views or forms.

Open-Awesome

mailchecker

MITPHP

Cross-language library to detect temporary (disposable/throwaway) email addresses, covering over 55,000 fake providers.

Visit Website GitHub

1.9k stars303 forks0 contributors

What is mailchecker?

MailChecker is a cross-language library designed to detect temporary (disposable/throwaway) email addresses. It validates email format and checks against a database of over 55,000 known fake email providers, helping developers prevent spam and ensure legitimate user communication.

Target Audience

Developers building web applications, SaaS platforms, or any system requiring user email validation, particularly those needing to block disposable email addresses to reduce spam and improve data quality.

Value Proposition

It offers a consistent, multi-language solution with an extensive, community-maintained database of disposable email domains, making it more reliable and easier to integrate than building custom validation logic for each project.

Overview

:mailbox: Cross-language temporary (disposable/throwaway) email detection library. Covers 55 734+ fake email providers.

Use Cases

Best For

Blocking disposable email sign-ups on registration forms
Reducing spam and fake accounts in web applications
Ensuring legitimate user contact for communication-heavy SaaS
Validating email addresses across multiple backend languages (Node.js, PHP, Python, etc.)
Maintaining clean user databases by filtering out temporary emails
Preventing abuse from throwaway email services like Yopmail

Not Ideal For

Applications requiring real-time email deliverability verification (e.g., sending confirmation emails to check inbox existence)
Projects where temporary emails are acceptable, such as beta testing environments or privacy-focused user onboarding
High-performance systems with strict memory constraints, as loading the 55,000+ domain list can increase resource usage

Pros & Cons

Pros

Cross-Language Consistency

Offers a uniform `isValid(email)` API across Node.js, PHP, Python, Ruby, Rust, and more, reducing integration complexity for multi-stack teams.

Extensive Disposable Database

Relies on a curated list of over 55,000 disposable domains from community sources like TorVPN, regularly updated to block services like Yopmail.

Dual Validation Layer

Combines format validation using established regex (validator.js) with disposable domain checks, ensuring both syntax and legitimacy in one call.

Community-Driven Updates

Allows contributors to add new domains to the shared list.txt file, keeping the database current without relying solely on maintainer updates.

Cons

Static List Limitations

New disposable email services emerge frequently, and the static database may have gaps unless manually updated, leading to missed domains.

Memory and Performance Overhead

Loading the large domain list into memory can increase startup time and resource usage, especially in serverless or lightweight environments.

API Breaking Changes

Major version upgrades (e.g., 1.x to 3.x) have introduced breaking API changes, requiring code adjustments and careful migration planning.

Frequently Asked Questions

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