I have come across a number of outlook webmail users who fail to set their default languages when logging in for the first time.  I have also found myself looking at screen below and wondering how exchange decided to print question marks (??????) when you run certain commands. If this sound like your problem then read on


In this case, the user had set the language on webmail to Chinese and had also chosen the option to rename folders to Chinese. The solution to this turned out to be much simpler than I thought.

Set-MailboxRegionalConfiguration -Language “fi-FI” -LocalizeDefaultFolderName:$true

This command is well document here and it saved me from pulling my few hairs.