Can I reply to an email from a Proton Pass alias?

Yes. Aliases created through Proton Pass (using SimpleLogin technology) support two-way mail, so you can reply from the alias without revealing your real address. A temp mail inbox is receive-only, so any service that expects a reply will stall. Check Proton's current documentation for the exact limits on your plan.

Is a Proton Pass alias more private than temp mail?

They protect different things. An alias hides your real address from the sender but still forwards mail to your real inbox, so your real inbox remains in the chain. A disposable inbox has no forwarding leg and expires, leaving no residual link. Neither encrypts the message itself, and neither is a substitute for a password manager.

What happens to accounts tied to a temp mail address after it expires?

You lose the ability to receive password resets, verification codes, or support replies at that address. If the account matters, that can mean permanent lockout. This is why anything you might need to recover later should use an alias or a real address instead of a disposable inbox.

Do paid aliases work with custom domains?

Yes, on paid plans. You can bring your own domain and generate aliases on it, which makes addresses look ordinary to recipients and lets you re-point them later. Temp mail addresses always sit on the provider's domain and cannot be customised. Confirm current plan details with Proton before buying.

Can I use either tool to get around a site's signup rules?

No. Using aliases or disposable inboxes to evade bans, dodge identity checks, or claim trials you are not entitled to breaches most platforms' terms and may have legal consequences. Both tools are intended for privacy and inbox tidiness, not for circumventing a service's rules.

Proton Pass Aliases vs Temp Mail: Which Fits Your Signup?

Proton Pass aliases (the SimpleLogin engine now built into Proton's password manager) and temp mail solve different halves of the same problem. A paid alias gives you a durable, reply-capable address that forwards to your real inbox and can be switched off later; a disposable inbox gives you a short-lived, receive-only address that needs no account and leaves nothing behind. Choose the alias when you need the address to keep working and you want a kill switch; choose temp mail when you need one code, once, and nothing more.

What a Proton Pass alias actually is

Proton acquired SimpleLogin, the alias-forwarding service, and folded its technology into Proton Pass. The mechanic is simple: you generate a random address such as quiet-otter-82@passinbox.com (the exact domains change, so check Proton's own documentation), and mail sent there is forwarded to your real mailbox. You never give the merchant your real address, but you do receive everything, including replies if you initiate them from the alias.

Three properties matter more than the branding:

It forwards, it does not store. The alias is a relay. Your real inbox is still where mail lands, which means your real inbox is still exposed to whatever the sender does with it.
It is tied to an account. You need a Proton account, and the alias management lives inside Proton Pass. That account is the thing that makes the kill switch possible.
It is a paid feature at scale. Proton offers a limited free allowance and charges for more aliases, custom domains and related features. The free tier is genuinely useful but not unlimited.

What a paid alias gives you that a throwaway inbox does not

Replies and two-way conversation

A temp mail inbox is receive-only. You cannot send from it, so any service that expects a reply, a confirmation, or a support thread will stall. An alias can send as well as receive, which makes it usable for ordinary correspondence, not just signups. If you have ever tried to reply to a support ticket from a disposable address, you already know the wall you hit.

Custom domains

With a paid plan you can bring your own domain and generate aliases on it. That gives you addresses that look ordinary to the recipient, survive the collapse of any one provider, and can be re-pointed later. A temp mail address lives on the provider's domain and dies with the inbox. That is fine for a one-off code and useless for anything you want to keep.

The on/off switch

This is the real prize. If an alias starts attracting spam, you disable it and the mail stops. You do not have to change your real address, and you do not have to unsubscribe from anything. The same applies if a service is breached: you turn off the alias and the leaked address becomes inert. A disposable inbox gives you a similar effect by expiring, but you lose access at the same time, which is a problem if you still need the account.

Persistence without exposure

An alias can live for years. You can log in to an old account, receive a password reset, and never reveal the address behind it. A temp inbox cannot do this: once it expires, the address is gone and any account tied to it is effectively orphaned. If you want to understand why that matters, our guide to recovering a temp mail address is blunt about the limits.

Where a disposable inbox wins

Temp mail is not a worse alias. It is a different tool, and in several situations it is the better one.

No account, no setup. You open a page, get an address, and receive a code. There is nothing to install, no password to remember, and no identity attached.
Nothing to leak later. An alias forwards to your real inbox, so your real inbox is still in the chain. A disposable inbox has no forwarding leg; when it expires, there is no residual link between you and the sender.
Speed. For a download gate, a forum lurker account, or a one-time promo code, a 60-minute inbox is faster than opening a password manager and generating an alias.
Honest ephemerality. You know the inbox will vanish. That forces you to treat the account as throwaway, which is often the correct posture. Our piece on temp mail vs VPN vs alias goes deeper on where each tool fits.

One caveat applies to both: some sites block disposable and alias domains outright. That is a policy decision by the site, not a technical failure, and it is worth reading why websites block disposable emails before you assume a code will arrive.

Proton Pass aliases vs temp mail: side by side

Feature	Proton Pass / SimpleLogin alias	Temp mail inbox
Can receive mail	Yes	Yes
Can send or reply	Yes	No
Account required	Yes (Proton account)	No
Custom domain	Yes, on paid plans	No
Lifespan	Indefinite until disabled	Typically minutes to hours
Kill switch	Yes, per alias	Expiry only
Forwards to real inbox	Yes	No
Cost	Free tier, then paid	Free
Best for	Long-lived accounts, replies, custom domains	One-off codes, downloads, throwaway signups

Which should you use for a given signup?

The decision usually comes down to one question: will you need this account again?

If yes, use an alias. Anything you might need to recover, pay for, or log into months later belongs on an address you control. That includes shopping accounts, software licences, and anything tied to money.
If no, use temp mail. A download gate, a forum you will read once, a promo code, a beta waitlist: these are exactly what a short-lived inbox is for. Our guide to free trials and promo codes covers the pattern.
If unsure, use the alias. The cost of being wrong is asymmetric. Losing access to an alias is inconvenient; losing access to an account because the inbox expired can be permanent.

What about two-factor codes and password resets?

Both tools can receive a one-time code, but only the alias keeps working long enough to be a recovery route. If an account uses email-based two-factor authentication, tying it to a disposable inbox is a self-inflicted lockout waiting to happen. Our explainer on how OTP verification works sets out why the receiving address needs to be durable for anything you care about.

Honest limits on both sides

Neither tool is a shield. An alias does not stop a determined sender from correlating behaviour, and it does not make a breached merchant trustworthy. A disposable inbox does not encrypt anything, and it is not a substitute for a password manager. What both do is reduce the blast radius of giving out an address, which is a narrower and more honest claim than "anonymous email".

There is also a policy line. Using either tool to evade a ban, dodge identity checks, or claim a trial you are not entitled to is a terms-of-service problem, and in some contexts a legal one. The tools are for privacy and tidiness, not for circumventing rules. Our overview of whether temp mail is legal is clear about where that line sits.

Sources

SimpleLogin documentation: https://simplelogin.io/docs/
Proton, Proton Pass support pages: https://proton.me/support

The bottom line

Proton Pass aliases and temp mail are complementary, not competing. Use an alias when the address needs to outlive the signup, when you want replies, a custom domain, or a kill switch you control. Use a disposable inbox when you need one code, once, with no account and no forwarding trail. If you are still deciding, start with the lighter tool and move up when a signup earns it. You can open a disposable inbox in seconds and see which side of the line your next signup falls on.