Mailinator is one of the oldest disposable-email services on the internet, and it's still the right answer for a specific reader: a QA engineer wiring up signup tests in Selenium, Cypress, Playwright, or Puppeteer who needs an inbox they can read with an API call and assert against in code. That's what Mailinator was built for. If that's you, stay.
For everyone else — anyone who landed here because they're using Mailinator for personal signups, newsletters, forum accounts, or anything carrying a verification code — there's a structural choice in how it works that's worth knowing about. By default, every Mailinator inbox is public. Anyone who knows or guesses your @mailinator.com address can read the messages inside it. That model is fine for the QA workflow it was designed for. It isn't what most people want when they're protecting their real email from a signup form. Here's the comparison.
What Mailinator does that SecondInbox doesn't
Two things to be straightforward about up front:
- Automated testing as a first-class use case. Mailinator publishes a documented REST API, ships SDKs for Ruby and JavaScript, and explicitly supports Selenium, Cypress, Playwright, and Puppeteer integrations. If you're running signup tests in CI and need to programmatically read a one-time code from an inbox, that's what Mailinator has been built for, for years. SecondInbox doesn't expose a public API today.
- Webhooks and routing rules on the free tier. The free Public plan includes webhooks for inbound mail and rule-based routing between inboxes. Useful if you're piping verification emails into a test orchestrator. SecondInbox is a browser-based inbox, not an automation platform.
If automated testing is your reason for using a temp email, this page isn't trying to change your mind. If it isn't, keep reading.
Where Mailinator falls short
The gaps worth naming for the non-developer reader:
- Free-tier inboxes are public by default. Mailinator describes the free Public plan as "100% free, public temporary or disposable email addresses." That's not a leaked footnote — it's the design. Anyone who knows or types your address into the Mailinator front page can read what's sitting inside it. If you're testing a signup flow with throwaway dummy data, fine. If a real password reset, OTP, or invite link lands in there, anyone watching can use it before you do. There's no way to make a free
@mailinator.cominbox private. The same structural pattern is true of Guerrilla Mail, which is worth knowing if you're shopping in this category. - Private inboxes require a separate "Verified Pro" application. Mailinator does offer private inboxes at no cost, but only via "Verified Pro" — a free tier you have to apply for. So the path from "I want a private temp inbox today" to having one isn't one click; it's an application form and a wait for verification. That's a friction step many users won't make it through.
- Permanent storage is paywall-gated. Free accounts get "Temporary Storage" only — messages don't persist. Even Verified Pro is capped at 10 MB and 60 emails per day. Anything more sustained costs $79 per month on the Business plan, billed annually. For a casual user, that's a steep cliff.
- Volume limits in the free private tier. Verified Pro caps you at 2,000 emails per month and 60 per day, with one user seat. Easy to bump into if you're actively using a private inbox, and there's no graceful overflow.
How SecondInbox compares
On the axes most users reach for a temp email for:
- Inbox privacy — Mailinator: Public on the free tier (anyone with the address can read) · SecondInbox: Private (tied to your browser session)
- Path to a private inbox — Mailinator: Apply for Verified Pro and wait · SecondInbox: One click, immediate
- How long the inbox lives — Mailinator: Temporary storage on the free tier; permanent storage starts at $79/mo · SecondInbox: 30 minutes, one-click extend, free
- Daily / monthly caps — Mailinator: 60 emails/day, 2,000/month on Verified Pro · SecondInbox: No volume cap on basic use
- Managing multiple addresses — Mailinator: 1 user on Verified Pro; more on paid tiers · SecondInbox: Free, with an optional free account
- API and automation — Mailinator: Full REST API, SDKs, Selenium/Cypress/Playwright/Puppeteer integration · SecondInbox: Browser-based only
- Paid tier / upsell — Mailinator: Paid plans from $79/mo to $699+/mo · SecondInbox: No paid tier
- Signup required — Mailinator: No (Public); application required (Verified Pro) · SecondInbox: No
The comparison underneath the table comes down to who the service is for. Mailinator is a developer tool that happens to also work as a public temp inbox. SecondInbox is a privacy tool for people receiving real signup emails — verification codes, account invites, password resets — and it's built to keep those private without an application or a paid plan in the way. Both are defensible designs. Which one fits depends on whether the inbox is going to hold a piece of code you'd rather not have a stranger read.
When SecondInbox is the better fit
This is most people who land on this page:
- You want your inbox to be yours, not public. SecondInbox inboxes are tied to your browser session — not a URL anyone who knows or guesses can open in their own browser. For anything carrying a one-time code, a verification link, or an account invite, that's the difference between a private receipt and a shared one.
- You're not running a CI pipeline. If you aren't asserting against an inbox API in test code, Mailinator's automation features aren't doing anything for you. A clean browser inbox is shorter to use for a one-off signup than configuring an API key.
- You want a private inbox today, not after an application review. SecondInbox is one click. No verification step, no approval to wait on, no daily quota.
- You don't want to think about which tier you're on. SecondInbox has no paid tier and no upsell path. Whatever you came to do, you do it without hitting an "upgrade for permanent storage" wall.
- You care about privacy as a default, not an add-on. No tracking cookies, no data sale. IP retained briefly for rate-limiting, then discarded. The privacy posture isn't gated behind an application or a paid plan — it's how the service works for everyone.
FAQ
Yes. Your inbox is tied to your browser session, not to a URL anyone else can read in their own browser. Mailinator's free Public plan is explicitly designed the other way — that's not a misuse, it's the model. For most signup-protection use cases, private is what you actually want.
Not today. Mailinator's API, webhooks, and Selenium / Cypress / Playwright / Puppeteer integrations are genuinely what it's built for. If your reason for reaching for a temp email is to automate signup tests in CI, Mailinator is the right tool — keep using it.
No. The free tier doesn't cap how many emails you can receive. Mailinator's Verified Pro caps at 60 per day and 2,000 per month; SecondInbox doesn't apply equivalent quotas to basic use.
No. One click on the homepage and the inbox is ready. There's no application, no verification step, no approval to wait on. That whole flow doesn't exist.
Sometimes. Major platforms maintain lists of known disposable-email domains, and SecondInbox can land on those lists the same way Mailinator does. For smaller sites, forums, and most newsletter-style signups, it's a non-issue.