User Configuration > Administrative Templates > Microsoft Outlook 2016 > Miscellaneous
User
HKCU\software\policies\microsoft\office\16.0\common\im
This policy setting controls the time-out interval of Outlook people search. Outlook returns as many people search results as possible before the time-out interval lapses. If the search results are incomplete, Outlook displays a message at the bottom of the results list. If you enable this policy setting, you can specify the time-out interval in milliseconds. If you disable or do not configure this policy setting, the time-out interval is 60,000 milliseconds (60 seconds).