How QR Device Linking Works in MailOnce
Follow the request from rotating QR code to browser approval and access on the second device.
Quick answer
MailOnce uses the QR code to carry a short linking request. The current browser receives the request and decides whether the second device may join the inbox.
Separate discovery from permission
A QR code can be seen or scanned by someone nearby, so the scan itself should never be the final authorization step. The approval prompt is the actual permission boundary.
Device linking keeps the task inside one active MailOnce inbox. The QR code is only a short request mechanism; access still depends on approval from the browser that already controls the inbox.
What the QR code does — and what it does not do
The code helps the second device announce that it wants to join. It is not the final permission. That distinction matters because a QR code can be visible to somebody nearby; the existing browser remains the place where access is deliberately granted or refused.
What actually grants access
The QR starts the conversation; browser approval grants access.
Try MailOnce
Move one active inbox between your own devices
Create a temporary inbox, then link another device only when your task genuinely moves from one screen to another.
Create temporary emailRelated device linking guides
Continue with the device-linking topics closest to what you just read.
How to Open the Same Temporary Inbox on Another Device
Continue with the inbox already receiving your messages instead of creating a second address.
Read guideWhy Does MailOnce Require Approval After Scanning the QR Code?
Understand why a scan starts a request but the existing session still controls permission.
Read guideIs QR Device Linking Safe?
See the security boundary of short-lived QR requests, explicit approval and recognized devices.
Read guide