Maximum Groups Supported

This policy setting controls the maximum number of groups that are accessible through the Navigation Pane in Outlook for Windows.

If you enable this policy setting, only the number of groups set in the Groups Count will be shown in the Navigation Pane.

If you don't enable this policy setting, the maximum number of groups displayed defaults to 1000.

Groups Count:

Registry Hive	HKEY_CURRENT_USER
Registry Path	software\policies\microsoft\office\16.0\outlook\options\groups
Value Name	maxgroupssupported
Value Type	REG_DWORD
Default Value	100
Min Value	100
Max Value	1000