Use legacy Change Password authentication dialog boxes
Supported on: At least Windows Server 2008 R2 or Windows 7
Registry
HKCU
software\policies\microsoft\office\16.0\outlook\rpc Value name: disablecredui
Enabled: disablecredui = 1
Disabled: disablecredui = 0
Description
By default, Outlook displays the Windows authentication dialog box when users are prompted to change their passwords. By enabling this setting, you can change this behavior so that older-style Outlook dialog boxes that include the Change Password button are displayed.