Hi MartinTrnka,
If you have a Microsoft Exchange account, contact groups are not saved to the Exchange server. Any groups that you create are saved on your computer and are available only in Outlook for Mac. Based on the current situation, I suggest you go to http://g.microsoftonline.com/0BX11EN/135 to submit feedback about this to help improve our service. Your time and efforts to our attention are highly appreciated.
Thanks,
Johnny Zhang
