I'm pretty sure that I sow on this forum automapping parameter - but now I can't find such information
At the moment when he want to open mailbox Y and Z he must klik on User icon and use Open another mailbox function.
Could someone give me powershell example how to set X to open automaticaly Z and Y everytime X logged on on OWA please.
Unfortunately Automapping feature is limited only to Outlook, I understand that you always wanted to have another mailbox open as soon as logged into Primary, there is an option to map another mailbox into Primary in OWA which can be a workaround for this scenario.
Follow the Step 1, Listed in below link: