You can configure this setting manually via the Registry Editor or deploy it across an organization using Group Policy Objects (GPO). Manual Registry Configuration completely. Press Windows Key + R , type regedit , and hit Enter.
Set value to 0 or delete the key.
Note: The DisableSyncSliderForSharedMailbox setting is primarily a . Mac users should rely on the built-in "Download all messages" option. disablesyncsliderforsharedmailbox
I have provided two versions: one formatted as a (suitable for IT admins), and a shorter version suitable for a Microsoft Feedback Portal (UserVoice) or internal change request. You can configure this setting manually via the