TL;DR
Temp Mail (temp-mail.org) and Guerrilla Mail are two of the oldest and most popular disposable email services. They have both been around for well over a...
Aspect
Temp Mail
Guerrilla Mail
Outbound Email
Nukemail is receive-only. You cannot send or reply to emails. It is strictly a one-way inbox for catching verification codes and confirmations. If a service requires you to respond to an email to complete verification, Nukemail can't handle that.
You can send and receive emails here. It is one of the few disposable services that lets you send mail, but you will find deliverability is inconsistent because many mail servers reject messages from guerrillamail.com domains. The sending feature works for niche situations but is unreliable for anything important.
Interface Design
Modern, clean interface with a mobile app for iOS and Android. Feels polished and contemporary. The app makes it easy to copy addresses and read emails on the go.
The interface is dated and hasn't seen real updates in years. It works fine but looks old, especially on mobile devices. The design feels like it belongs in the early 2010s, but the underlying functionality remains reliable.
Domain Blocking
Temp-mail.org domains are blocked almost everywhere because the service is so popular. If you try to sign up for Netflix, Spotify, Discord or most other mainstream services with a Temp Mail address, the registration will fail right away.
They get blocked just as often. After nearly two decades, guerrillamail.com and its variants are among the first domains added to any blocklist. That is the price of being a well-known service. The domains that everyone knows about are the domains that every website blocks.
Inbox Lifetime
Your inbox stays active as long as you keep the tab open or the app running. There is no fixed timer because the duration is unpredictable. If you close your browser, the inbox might be recoverable or it might be gone depending on your current cookie state.
It takes about 1 hour. It's tied to your browser session and resets with activity. It's shorter than most alternatives. This window is fine for quick verifications but it's problematic for slower email systems.
Address Choice
Random address assigned. No ability to choose your own username. The address looks obviously auto-generated, which can trigger anti-spam systems that scan for patterns.
You can choose your own custom inbox name. You type whatever you want before the @ symbol, so you have control over how the address looks. A name like
[email protected] looks more natural than a random string of characters.
Privacy
Your inbox stays private because it is only accessible through your browser session. The service loads ads and third-party trackers though. This undermines the privacy proposition. Advertising networks may track your browsing behavior while you are on the Temp Mail site.
Private inboxes with a longer track record of operation. Minimal tracking compared to Temp Mail. Guerrilla Mail has generally maintained a more privacy-respecting stance regarding third-party scripts.
Mobile Experience
We have mobile apps for iOS and Android that work much better than the web version on phones and send push notifications when new emails arrive.
There is no mobile app. The web interface isn't tuned for mobile screens so it can be difficult to navigate on a phone. You'll need to use your mobile browser. It works, but it isn't the ideal experience.
Ad Load
Heavy advertising that can slow down the page and interfere with functionality, especially on mobile. Some users report difficulty reading emails due to overlay ads and auto-playing video advertisements.
Moderate advertising. Less intrusive than Temp Mail but still present. The ads do not typically interfere with reading emails or copying verification codes.
Verdict
Temp Mail has a better interface and works better on mobile. If you use disposable email mostly on your phone, Temp Mail's dedicated apps give you a clear advantage over the unoptimized web interface you get with Guerrilla Mail.
Guerrilla Mail is the better choice if you need the ability to send an email because that is a rare but sometimes critical need. It also offers custom inbox names so you have slightly more control over how your address looks.
Both services have a common problem because their domains are on every major blocklist. You'll find that neither service works if you're trying to sign up for a mainstream website. NukeMail fixes this with fresh and regularly rotated domains. These look like normal email addresses so they pass most automated checks.
If you're frustrated because websites block your temp email address, try a newer service that uses fresh domains. NukeMail monitors the reputation of its domains and rotates them before they end up on blocklists. This keeps your acceptance rates high when you sign up for new accounts.
The long lifespan of these services is both good and bad. They are proven and reliable because they have survived for nearly two decades and aren't going anywhere soon. Their age is also a downside because their domains are firmly stuck on every blocklist. New services have a window of time where they actually work before their domains become common knowledge. That is a natural advantage that older services just can't match.