User Configuration > Administrative Templates > Microsoft Outlook 2016 > Outlook Options > Preferences > E-mail Options > Advanced E-mail Options > Desktop Alert
User
HKCU\software\policies\microsoft\office\16.0\common\desktopalerts
You can change the default location of the Desktop Alert. In the Corner field, select a number corresponding to a quadrant of the user's screen: 0 = upper left, 1 = upper right, 2 = lower left, 3 = lower right (the default). In the XOffset field, enter a number representing the horizontal distance from the corner you've specified (the default is 44). In the YOffset field, enter a number representing the vertical distance from the corner you've specified (the default is 42).