Cached Exchange Mode GPO won't set to 1 month

Question

We are on Exchange Online and working on efficiency, so are trying to implement Exchange Cached Mode. We need to set the cached sync settings to 1 month, but when we try it sets to "All" instead.

Is this an error in the admx? Is there another way to get it to actually get it to cache for 1 month?

Answer 1

Hi @Mark R
Did you select the One month for cached exchange mode sync settings for profiles?

Then you can see this:

And the following registry data is used by Outlook:

Key: HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\16.0\Outlook\Cached Mode
DWORD: SyncWindowSetting
Value: integer value (Decimal) specifying the number of months (use only the following values)

0 = All (whole mailbox)
1 = 1 month of email items
3 = 3 months of email items
6 = 6 months of email items
12 = 12 months of email items
24 = 24 months of email items

Details: https://learn.microsoft.com/en-US/outlook/troubleshoot/user-interface/only-subset-items-synchronized#feature-administration-through-group-policy

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Answer 2

You can try setting the cached sync settings to 1 month by editing the registry key. To do this, open the registry editor (regedit) and navigate to the following registry key:

HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Cached Mode

Once you are in the registry key, create a new DWORD (32-bit) value and name it “SyncWindow”. Set the value to 1 to enable a one-month sync window. After making the changes, restart Outlook and the sync window should now be set to one month.