When it comes to email testing, having access to reliable email inboxes can save your team hours of development time. Mailinator is widely known for its free public inboxes that anyone can use for temporary email. These public inboxes are excellent for quick, disposable testing, but for more advanced use cases—such as One Time Password (OTP) testing or secure workflow testing—Mailinator’s private testing domains (included in the free Verified Pro plan or paid subscriptions) provide significantly more value.
Public Inboxes: Fast, Free, and Shared
Public inboxes are the simplest way to get started with Mailinator. Just send an email to any @mailinator.com address, and you can instantly view the message in the public web interface. This is perfect for:
- Testing user registration flows with a throwaway address
- Checking email formatting or links quickly
- Using a disposable email to avoid spam
However, because they’re shared, anyone can view the messages in these inboxes. That makes them unsuitable for testing sensitive scenarios like OTP verification or user-specific transactional workflows.
In addition, the public Mailinator domain has an array of protective filters and blocks to prevent fraud and abuse. Because the public domain is truly intended for occasional personal use, sending larger volumes of messages can trigger a block and abuse warning from the system.
Private Testing Domains: Secure, Automated, and Enterprise-Ready
For teams running software testing at scale, Mailinator’s private domains offer significant advantages:
- Privacy & Security – Only your team can access the inboxes, preventing exposure of sensitive test data.
- Automation APIs – Access emails via API for fully automated QA pipelines.
- Scalable OTP Testing – Validate time-sensitive One Time Passwords in bulk without risking interception.
- Test at Production Speed – Handle millions of emails per hour in dedicated domains.
Even better, the Verified Pro plan (free upgrade) gives you your own private testing domain, making it the best starting point for serious testers. Paid subscriptions unlock even more features like SMS testing and load testing options.
The Bottom Line
If you just need a quick temporary email inbox, public Mailinator inboxes do the trick. But if your QA team requires automation, security, and reliability for OTP testing and complex workflows, a private domain is the way to go. Start with the free Verified Pro plan to unlock these benefits and take your software testing to the next level.