Hi @Admin ,
To disable read sync for one device when logging in to the same email on multiple devices, you can follow these steps:
- Sign in to Outlook on the web.
- Choose Settings > General > Mobile devices.
- Select the device you want to disable read sync for from the list.
- Choose to delete the device partnership.
Please note that removing the device partnership will prevent read status synchronization between that device and your mailbox. However, it will not delete the email account from your phone.
It’s worth mentioning that using POP to achieve this purpose is no longer available in Office 365.
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