Mailtrap
Email testing and sending platform for developers. Provides a sandbox inbox for testing, plus Email API and SMTP for production sending with deliverability monitoring.
Use Cases
Free Tier
4,000 emails/month, 150/day, 1 domain, 1 user, 3 days of logs
How to Maximize the Free Tier
Mailtrap's free tier (4,000 emails/month, 150/day) is best used as a development sandbox — test your email templates, transactional flows, and integrations without worrying about spamming real users. The sandbox inbox is Mailtrap's killer feature: all emails are caught in a virtual inbox where you can inspect headers, HTML rendering, and attachments. For production sending, the same SMTP/API credentials work — just switch from sandbox to live mode. The 150/day limit means you'll want to avoid using Mailtrap for production bulk sends. Set up your domain's SPF and DKIM records early to ensure proper authentication.
Getting Started
Sign up at mailtrap.io → create a sending domain → verify with SPF/DKIM DNS records → choose between sandbox (testing) or live sending (production) → configure your app's SMTP settings with Mailtrap credentials → send a test email → check the inbox and delivery logs.
Pros
- Sandbox inbox: Built-in email testing sandbox catches all outgoing mail without hitting real inboxes — perfect for development
- Unified workflow: Same platform for testing in development and sending in production — no context switching
- Deliverability tools: Built-in spam score checking, link validation, and domain authentication guidance
Cons
- Low daily limit: 150 emails/day is restrictive for teams with multiple developers sending test emails simultaneously
- Short log retention: Email logs only persist for 3 days on the free plan — insufficient for debugging intermittent issues
- Single user: Only 1 user on the free plan — team collaboration requires upgrading to a paid tier