To create the mailbox default folders in the desired language for any new mailbox, please do the following:
1) Log on to MAgE host server with the service account used by MAgE.
2) Click on Start button and select Control Panel.
3) Click on Region and Language.
4) Click on Keyboards and Languages tab.
5) Click Change keyboards button.
6) On the General tab select appropriate language from the Default input language dropdown list.
7) Click OK.