In classic Outlook for Windows, synchronization cannot be completely “removed,” but cached (offline) synchronization can be disabled or cleared.
To effectively get rid of cached synchronization for a folder that is causing issues:
- In Outlook, right‑click the folder (for example, Inbox) where sync problems occur.
- Select Properties.
- On the General tab, select Clear Offline Items.
- Select OK, then let Outlook resync or switch to online mode.
To avoid cached sync issues altogether, use Outlook in online mode instead of cached mode. This stops Outlook from keeping and synchronizing an offline copy of the mailbox.
If synchronization problems involve a mobile device (phone/tablet) connected to the same mailbox, remove the device partnership so it no longer syncs:
- Sign in to Outlook.com or Outlook on the web.
- Go to Settings > General > Mobile devices.
- Select the device and delete the device partnership, then Save.
- Power off and restart the device before using email again.
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