One inbox · two screens · one approval
Use the Same Temporary Email Inbox on Your Phone and Computer
Your verification started on the laptop. The message you need would be easier to open on your phone. Creating another temporary address would split the flow in two. MailOnce device linking is designed for the opposite: open the same active temporary inbox on another device with a QR request that the current browser must approve.
Screen A
The inbox already lives here
This browser controls the active MailOnce inbox. The address has already been submitted, and messages are already arriving here.
Screen B
You want the same inbox here
Not a copied address. Not a second mailbox. The goal is continuity: another device joins the inbox that is already active.
The handoff
How QR device linking works in MailOnce
Open device linking
From the active inbox, start the device-linking flow. MailOnce presents a short-lived, rotating QR request for this handoff.
Scan the QR code on the second device
The scan identifies the linking request. It does not silently grant the second device access to the inbox.
Return to the browser that already owns the inbox
The existing session receives the request and remains the decision point.
The scan asks. The current inbox answers.
Approve or refuse
Approve only when the request matches the device you are holding. If it is unexpected, refuse it.
Continue in the same temporary inbox
After approval, the second device joins the existing inbox. Linking does not create a new temporary email address.
Is QR device linking safe?
The useful security model is short request + explicit approval + a device you recognize. A rotating QR request reduces the value of an old request, while approval keeps the existing session in control of whether another device joins.
Expected request
You opened linking, scanned the code yourself, recognize the second device and are still completing the same task.
Unexpected request
You did not start device linking, cannot identify the requesting device, or the request appears after you stopped trying to connect anything.
What should you do with an unexpected device-link request?
Refuse it. A request you did not initiate has no reason to be approved merely because it appeared. Keep control with the device already using the inbox and start a fresh linking flow later if you actually need another device.
What linking changes — and what it does not
Does linking another device create a new temporary inbox?
No. The point of device linking is to keep one temporary email workflow intact across your own screens. The address remains the same, incoming messages belong to the same active inbox, and the linked devices follow that inbox's existing lifetime.
Device linking vs forwarding an email or OTP code
Forwarding creates another copy or moves information into another communication channel. Device linking keeps you inside the original temporary inbox. That distinction matters during verification: instead of copying an OTP or verification message somewhere else just to reach another screen, you can continue the same inbox session on the second device.
The linked device does not make the OTP newer, extend its validity or change the sender's verification rules. It simply gives the approved device access to the same MailOnce inbox where the message arrived.
Understand OTP and verification codesA common cross-device moment
Signup on laptop. Verification on phone. Still one inbox.
Imagine a signup form is open on your computer, but the verification link is easier to use on your phone. Changing the temporary address would break the signup you already started. Device linking preserves the address and moves access to the screen where you need it.
The reverse works as a mental model too: start on mobile, continue reading the same temporary inbox on a computer. The important part is not which device comes first. It is that the second device joins only after the current session approves the request.
Keep the inbox. Change the screen.
Open the same temporary inbox on another device
Use secure device linking when the active address is already part of a task and you simply need that same inbox on your phone, tablet or computer.
Create a temporary inboxContinue through the Knowledge Center
Same inbox, different screen — what should you understand next?
Continue with the inbox lifetime, incoming-message flow, or safe handling once the second device is approved.
Same deadline
Inbox Lifecycle
Linked devices share the same active inbox and therefore the same underlying inbox lifetime.
Follow the clock →Same messages
Receive Messages
See how incoming mail reaches the inbox and appears while you continue the workflow across devices.
Trace incoming mail →Same caution
Safe Email & Link Handling
A second screen does not change whether a sender, link or requested action should be trusted.
Handle messages safely →