Guerrilla Mail has been around since 2006. If you're using it to send disposable email or to drive a workflow against its JSON API, it's doing something SecondInbox doesn't - full stop. Stay.
For anyone else reading this page - privacy-minded users who picked Guerrilla Mail because it was free and didn't ask for a signup - there's a structural choice in how it works that's worth knowing about: Guerrilla Mail inboxes have no password. Anyone who knows your address can read what's inside. Their own site recommends the Scramble Address feature to work around it. That model, combined with a 60-minute auto-delete and a UI that hasn't been refreshed in years, is where SecondInbox lands differently. Here's the comparison.
What Guerrilla Mail does that SecondInbox doesn't
Two things to be straightforward about up front:
- Sending email. Guerrilla Mail lets you compose and send from the disposable address. That's genuinely rare - most temp-email services, SecondInbox included, are receive-only. If part of your workflow requires sending, even once, SecondInbox won't cover that.
- A public JSON API. Guerrilla Mail publishes a documented JSON API and has mature Python and Node clients. If you're automating signup tests or crawling responses programmatically, that's already there. SecondInbox doesn't expose a public API today.
If either of those is core to what you're doing, this page isn't trying to change your mind. If neither is, keep reading.
Where Guerrilla Mail falls short
The gaps worth naming:
- The inbox is publicly accessible. There's no password, no account gate. Anyone who knows or guesses your Guerrilla Mail address can read what's sitting in the inbox. Guerrilla Mail acknowledges this and offers a "Scramble Address" feature to make addresses harder to guess - but the underlying model is still "security by obscurity." For a newsletter signup it's fine. For anything carrying a password reset link, a one-time code, or an invite you don't want forwarded, it's not.
- 60-minute fixed retention. Emails auto-delete an hour after delivery, and there's no easy way to hold an inbox open longer without paying. That's a problem for slow confirmation emails, multi-step signups that pause between messages, or anything you want to scan later the same day.
- Dated interface. The UI hasn't had a meaningful refresh in years. Frame-style layout, small controls, limited mobile responsiveness. Reviews have noted this consistently - it works, but it feels like software from 2010.
How SecondInbox compares
On the axes most users reach for a temp email for:
- Inbox privacy - Guerrilla Mail: Public (anyone with the address can read) · SecondInbox: Private (tied to your browser session)
- How long the inbox lives - Guerrilla Mail: 60 minutes, fixed · SecondInbox: 30 minutes, one-click extend, free
- Managing multiple addresses - Guerrilla Mail: One at a time on free · SecondInbox: Free (with optional free account)
- UI and mobile experience - Guerrilla Mail: Dated, mobile-limited · SecondInbox: Current, responsive
- Paid tier / upsell - Guerrilla Mail: Yes (paid tier for own-domain + access controls) · SecondInbox: No paid tier - everything's free
- Signup required - Guerrilla Mail: No · SecondInbox: No
- HTML email + attachments - Both: Yes
What the comparison doesn't capture is the privacy philosophy. Guerrilla Mail treats the inbox as a public resource and hands you workarounds (Scramble Address, short retention) to reduce risk within that model. SecondInbox treats the inbox as yours for your session - not a URL anyone can guess their way into. Both are defensible designs. Which one fits depends on what you're putting through the inbox. A forum signup? Either works. A password reset link? Not the one anyone can read.
When SecondInbox is the better fit
This is most people reading 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 the address can read. That alone makes it the right choice for anything sensitive: password resets, one-time codes, account invites, anything you wouldn't want forwarded or read by a stranger.
- You want a modern, mobile-first interface. Built for how people actually use the web today. Responsive on phones, clean on desktop, no frame-style layout hangovers from 2010.
- You need the inbox to live longer than 60 minutes - without paying. The default is 30 minutes, but the one-click extension is free and doesn't require an account. No arbitrary auto-delete you can't control.
- You want multiple addresses, also without paying. An optional free account unlocks managing several addresses across sessions. Everything stays free - there's no paid tier to upsell you into.
- You care about privacy as a default, not an add-on. No tracking cookies, no data sale, no ad networks loading on the page. The IP is retained briefly for rate-limiting and then discarded. The privacy posture isn't a "Scramble Address" band-aid on a public model - it's how the service is built.
- You want a temp email that just works - no captcha, no upsell, no friction. One click, inbox ready. No "upgrade for more features" wall. Whatever you came to do, you do it and leave.
FAQ
Yes - in the practical sense that matters. Your inbox is tied to your browser session, not to a URL anyone who knows the address can open. There's no "scramble" workaround because the design doesn't need one. Someone watching the address over your shoulder still sees what's delivered, of course - but no third party is reading it just because they guessed the name.
Yes. The one-click extension is free and doesn't require an account. If you need persistent addresses across sessions, the optional free account lets you manage multiple inboxes - still no paid tier.
Free. No paid tier. Everything the service offers is available without paying, including the optional account for managing multiple addresses. There's nothing to upgrade to.
Some of them, sometimes. Major platforms maintain lists of known disposable-email domains, and SecondInbox lands on some of those lists the same way Guerrilla Mail does. For smaller sites, forums, and most newsletter-style signups, it's a non-issue.
No. SecondInbox is receive-only by design. If sending from the disposable address is core to your workflow, Guerrilla Mail is the better choice.