mailtester

Appearance

Changelog ​

All notable changes to @mailtester/core are documented here.

The format is based on Keep a Changelog and this project adheres to Semantic Versioning.

1.2.0 — 2026-07-12 ​

Latest release on npm: @mailtester/core@1.2.0

Changed ​

  • Disposable detection now uses detect-disposable-email ^1.1.0 (resolves to 1.1.1+) instead of the unmaintained disposable-email-domains package
  • Domain dataset expanded to ~167k exact-match domains + 399 wildcard bases (multi-source, actively maintained)
  • Matching includes wildcard subdomains (e.g. x.y.10mail.org) and IDN-aware lookups — not only exact domain equality
  • Node.js requirement raised to ≥ 20.0.0 (aligned with detect-disposable-email and current LTS)

Fixed ​

  • Early exit no longer stops on warning-severity results (e.g. typo suggestions). Previously, with default earlyExit: true, a typo warning could skip disposable (and later) checks — so addresses like user@gmaill.com could pass overall validation without a disposable check

Removed ​

  • Dependency on disposable-email-domains and fragile require() / JSON-file load fallbacks

Notes for consumers ​

  • Public API is unchanged (validate(), config keys, error codes, whitelist / blacklist / pattern options)
  • Behavior is intentionally stricter: more temporary / burner domains are blocked. Major free providers (Gmail, Outlook, Proton, etc.) remain allowed
  • If a legitimate domain is flagged, use validators.disposable.customWhitelist or report it for a data fix upstream in detect-disposable-email

Upgrade ​

bash
npm install @mailtester/core@1.2.0
# requires Node.js 20+

1.1.3 — 2026-05-06 ​

Fixed ​

  • Added co.in to typo detector TLD list for better Indian email validation

1.1.2 — 2026-01-20 ​

Changed ​

  • Replaced mailcheck dependency with custom Levenshtein distance implementation
  • Improved typo detection algorithm with better accuracy
  • Reduced bundle size by removing external dependency

Removed ​

  • mailcheck dependency (deprecated library, last updated 2014)
  • @types/mailcheck type definitions

Added ​

  • Custom string distance utilities (levenshteinDistance, similarityScore, findClosestMatch)
  • Enhanced typo detection with 60+ popular domains and 100+ TLDs
  • Smart typo detection that avoids false positives

Fixed ​

  • Typo detection now properly handles correct domains without suggesting changes
  • Improved confidence scoring for typo suggestions

1.1.1 — 2026-01-20 ​

Changed ​

  • Replaced mailcheck dependency with custom Levenshtein distance implementation
  • Improved typo detection algorithm with better accuracy
  • Reduced bundle size by removing external dependency

Removed ​

  • mailcheck dependency (deprecated library, last updated 2014)
  • @types/mailcheck type definitions

Added ​

  • Custom string distance utilities (levenshteinDistance, similarityScore, findClosestMatch)
  • Enhanced typo detection with 60+ popular domains and 100+ TLDs
  • Smart typo detection that avoids false positives

Fixed ​

  • Typo detection now properly handles correct domains without suggesting changes
  • Improved confidence scoring for typo suggestions

1.1.0 — 2026-01-20 ​

Changed ​

  • Node.js support expanded from 18.0.0 to 16.0.0 for broader compatibility
  • Updated documentation to reflect Node 16 support

Updated ​

  • Root package.json engines: >=16.0.0
  • @mailtester/core package.json engines: >=16.0.0
  • README.md requirements section
  • Documentation site (getting-started.md, why.md)

1.0.0 — 2025-11-28 ​

🎉 First Stable Release! ​

This is the first stable release of @mailtester/core.

Added ​

Core Validation ​

  • RFC 5322 Compliant Regex Validator — Full email format validation with strict and loose modes
  • Typo Detection — Suggests corrections for common domain typos (e.g. gmaill.com → gmail.com)
  • Disposable Email Blocking — Detects 40,000+ temporary email services with pattern-based detection
  • MX Record Validation — Verifies domain has valid mail servers with retry logic and quality scoring
  • SMTP Verification — Checks if mailbox actually exists with greylisting detection

Bulk Validation ​

  • Concurrent Processing — Validate thousands of emails with configurable concurrency limits
  • Progress Tracking — Real-time progress callbacks for bulk operations
  • Rate Limiting — Built-in token bucket algorithm with per-domain and global limits
  • Error Handling — Continue on error option for resilient batch processing

Configuration ​

  • Preset Configurations — Three built-in presets: strict, balanced, permissive
  • Flexible Configuration — Enable/disable individual validators, set timeouts, early exit options
  • TypeScript First — Full type safety with strict mode and comprehensive type definitions

API ​

  • validate(email, options?) — Single email validation
  • validateBulk(emails, options?) — Bulk email validation with concurrency control
  • createValidator(config?) — Create reusable validator instances with custom configuration

Performance ​

  • 3x Faster — Optimized validation pipeline
  • Lazy Loading — Disposable domain dataset loaded on-demand
  • Lightweight — ~25KB gzipped

Technical Details ​

  • Node.js 16+ required
  • TypeScript 5.3+ with strict mode
  • Dual Module Support — ESM and CommonJS exports
  • 90%+ Test Coverage — 644 tests covering all functionality
  • Zero Config — Sensible defaults, works out of the box

Dependencies ​

  • disposable-email-domains — Disposable email domain dataset

1.0.0-beta.1 — 2025-11-27 ​

Added ​

  • Initial beta release with all core features
  • See 1.0.0 for full feature list

Roadmap ​

Shipped in v1.2.0 ​

  • Migrated disposable detection to detect-disposable-email (~167k domains + wildcards)
  • Node.js 20+ requirement
  • Early-exit fix so typo warnings do not skip disposable checks

Planned for v1.3.0 ​

  • Enhanced reputation scoring with configurable weights
  • In-memory LRU caching for improved performance
  • Domain reputation database / MX quality scoring enhancements

Planned for v1.4.0 ​

  • Plugin system for third-party integrations
  • Browser-compatible build
  • Custom validator plugins