Is Firefox Relay the same as a disposable email address?

No. Firefox Relay creates masks that forward mail to your real inbox, so the address keeps working as long as your Relay account exists. A disposable email address is a standalone inbox that receives mail directly and expires after a set time. Relay hides your address; temp mail replaces the inbox.

Can I use Firefox Relay to receive one-time verification codes?

Yes, codes sent to a Relay mask are forwarded to your real inbox, so they arrive normally. The catch is that you are still exposing your real mailbox to whatever tracking the sender includes. For a single signup you will never revisit, a disposable inbox keeps the message away from your real account entirely.

What happens to accounts registered with a temp mail address?

Once the inbox expires, you cannot receive further mail at that address, and it cannot be recovered. Password resets, receipts and security alerts will be lost. Only use a temp address for accounts where losing access costs you nothing.

Do websites block Firefox Relay masks?

Some do, but far fewer than block disposable domains. Because Relay forwards rather than providing a throwaway inbox, the address a site sees is a stable Mozilla domain. Blocking behaviour changes often, so test with the specific service rather than assuming.

Should I use a mask or a temp inbox for a free trial?

Use a mask if a payment method is attached, because you may need cancellation confirmations, receipts or dispute evidence later. Use a temp inbox for trials with no card and no ongoing relationship, where the only message you need is the initial activation link.

Firefox Relay vs Temp Mail: Masks or Disposable Inboxes?

Firefox Relay and temp mail solve related but different problems. Firefox Relay creates email masks that forward messages to your real inbox, so you can hide your address without losing access. A temp mail service gives you a separate disposable inbox that receives mail directly and expires. If you want a permanent shield around your real address, choose Relay; if you want an inbox that never touches your real address and disappears after use, choose temp mail. The rest of this guide explains where each one works, where it breaks, and how to combine them sensibly.

What each tool actually does

It helps to be precise about the mechanics, because the difference drives every other trade-off.

Firefox Relay is Mozilla's email masking service. You generate an alias such as a random string at a Mozilla-owned domain, give that alias to a website, and Relay forwards whatever arrives to your real mailbox. Replies can be sent from the mask, so it behaves like a lightweight forwarding address. Because forwarding depends on Mozilla's infrastructure, the mask keeps working as long as your Relay account exists. Mozilla publishes the current feature set and limits on its support pages, and the free tier has historically allowed a small number of masks with the option to pay for more.

Temp mail is a standalone inbox. You open a service, get a random address, and read messages in the browser. There is no forwarding to your real account, no password to manage, and no long-term identity. MailboxTemp, for example, keeps an inbox for 60 minutes with the option to extend by 10 minutes at a time, and Pro inboxes last 24 hours. Addresses are random and receive-only.

That single architectural difference — forwarding versus standalone inbox — explains almost everything else.

Firefox Relay vs temp mail: side-by-side

Feature	Firefox Relay	Temp mail
Where mail lands	Your real inbox, via forwarding	A separate web inbox
Lifetime	As long as the mask and account exist	Minutes to hours (60 minutes on MailboxTemp, extendable; 24 hours on Pro)
Can you reply?	Yes, from the mask	No, receive-only
Account needed	Yes, a Mozilla account	No
Free allowance	Small number of masks; more with a paid plan	10 inboxes per IP per day on the free tier
Link to your identity	Masks are tied to your Relay account	None by design
Best for	Long-term signups you want to keep	One-off signups, codes, trials, testing
Recovery after expiry	Mask persists; mail still arrives	Inbox is gone; address cannot be recovered

Neither column is universally better. They are aimed at different moments in the life of an online account.

When is Firefox Relay the better choice?

Relay wins whenever you need to keep receiving mail from a sender over time without handing over your real address.

Accounts you intend to keep. A newsletter, a shop, a utility portal. The mask keeps forwarding for as long as you keep the Relay account, so a password reset three years from now still reaches you.
Senders that block disposable domains. Because Relay forwards rather than providing a throwaway inbox, the address a site sees is a stable Mozilla domain. Some sites still object, but the blocklists aimed at temp mail domains generally do not cover masks.
Two-way conversations. If you need to reply from the alias — a support thread, a marketplace seller — Relay supports that. Temp mail is receive-only, so replies are not an option.
Compartmentalising your real address. One mask per merchant makes it easy to see who leaked or sold your address, and you can disable a single mask without changing anything else.

The cost is that Relay is not anonymous in the way a disposable inbox is. Masks are tied to your Mozilla account, and forwarded mail lands in your real mailbox, where it is subject to whatever tracking pixels and filters already apply. If your goal is to keep a sender away from your real inbox entirely, forwarding is the wrong shape of tool.

When is a temp mail inbox the better choice?

Temp mail wins when the address is genuinely disposable — you need it once, briefly, and never again.

One-time verification codes. Sign up, receive the code, done. MailboxTemp detects one-time codes automatically, which saves hunting through a message. Our guide to how OTP verification works covers what to expect.
Downloads and gated content. Whitepapers, trials, coupon pop-ups. If the sender has no reason to contact you again, a disposable inbox is the honest tool.
Testing your own signup flows. Developers need addresses that do not pollute a real mailbox. See disposable email for developers for automation patterns.
Situations where you do not want any link to your identity. No account, no forwarding, no trail into your real inbox.

The limits are equally clear. The inbox expires, so anything sent later is lost. There is no recovery — our honest answer on whether you can recover a temp mail explains why. And you cannot send mail, which matters if a site asks you to reply to confirm.

What breaks with each approach?

Firefox Relay

Relay's weak points are account dependence and forwarding friction. If you lose access to your Mozilla account, managing masks becomes difficult. Some senders treat forwarded mail cautiously because the visible sender path includes the forwarding hop, which can affect spam scoring. Attachments and rich formatting usually survive, but it is worth checking the first message from any important sender. And the free mask allowance is small, so heavy use pushes you towards a paid plan — a reasonable trade, but a cost nonetheless.

Temp mail

Temp mail's weak points are expiry and blocking. Codes sent after the inbox closes are lost. Sites that check against disposable-domain lists will refuse the address outright; our post on why websites block disposable emails covers what to do when that happens. Recovery flows, purchase receipts and two-factor enrolment should never depend on an inbox that will vanish. If a service uses email as its only recovery channel, a temp address is a trap you set for yourself.

Can you use both together?

Yes, and for many people that is the sensible setup. A common pattern is to keep a small number of Relay masks for accounts that matter — banking-adjacent services, long-running subscriptions, anything with a payment method attached — and use temp mail for everything ephemeral: trials, forums, downloads, one-off codes.

The dividing line is simple: will I need to receive mail from this sender in a month? If yes, use a mask. If no, use a disposable inbox. If you are unsure, treat it as a yes — recovering a lost account is far more painful than deleting an unwanted newsletter.

One caveat applies to both: neither tool protects you from phishing. A mask can forward a convincing fake just as easily as a genuine message. Check links before clicking, as described in how to spot a phishing email.

Which should you pick for specific tasks?

Task-by-task, the answer usually falls out of the lifetime question.

Free trial with a card attached. A mask, so cancellation confirmations reach you. Temp mail risks losing the receipt.
Forum or community signup. Temp mail is fine if you only need the activation link; a mask if you plan to stay.
Downloading a file. Temp mail, every time.
Two-factor enrolment. Neither, ideally — use an authenticator app or passkey. Email 2FA on a disposable inbox is a lock with a paper key. See two-factor authentication explained.
Testing a signup flow. Temp mail, because you can burn addresses freely.
Newsletter you actually want. A mask, so you can switch it off later without unsubscribing from a dozen lists.

If you are still weighing broader options, temp mail vs VPN vs email alias sets these tools against each other at a higher level, and email aliases vs disposable email digs into the alias side specifically.

Sources

Mozilla Support — Firefox Relay help articles: https://support.mozilla.org/en-US/products/relay
Mozilla — Firefox Relay product page: https://relay.firefox.com/
RFC 5322, Internet Message Format (message headers and addressing): https://www.rfc-editor.org/rfc/rfc5322.html

The bottom line

Firefox Relay and temp mail are complementary, not competing. Relay is a long-lived shield that forwards to your real inbox — pick it for accounts you intend to keep, anything with a payment method, and senders that block disposable domains. Temp mail is a standalone inbox that expires — pick it for one-off codes, downloads, trials and testing, and never for recovery or two-factor. If you want to try the disposable side, open an inbox and see how the timer suits you; the service is receive-only, so keep a real or masked address for anything you need to answer.