Do not expand Contact Groups

Supported on: At least Windows Server 2008 R2 or Windows 7

Registry

HKCU software\policies\microsoft\office\16.0\outlook\options\mail

Value name: disabledlexpansion

Enabled: disabledlexpansion = 1

Disabled: disabledlexpansion = 0

Description

This policy setting controls whether Outlook users can expand Contact Groups when addressing e-mail messages. If you enable this policy setting, Outlook users cannot expand Contact Groups. If you disable or do not configure this policy setting, when Outlook users add a Contact Group to the To, CC, or BCC fields of an e-mail message or other item, they can expand the Contact Group to see the e-mail addresses of everyone in the group.