We've used Mailinator at Vartopia for years for QA email testing across signups, password resets, OTPs, and verification flows. The private domain feature is exactly what we needed — branded, isolated test addresses with reliable inbox catching that just works. The web UI is clean, fast, and easy for non-technical QA folks to navigate. Setup is essentially zero. But what really sets Mailinator apart is the support team — shoutout to Martha and Jack, who have been responsive, friendly, and genuinely helpful every time we've reached out. That kind of customer service is rare, and it's the reason I keep recommending them.

Their API is lovely to automate the E2E tests of email verification.

Mailinator provides Email inboxes for testing and monitoring email deliveries, Email content can be viewed.