You can backup your mailbox when you synchronize it with Microsoft Outlook on your local computer. In this order select the appropriate type of project and you point PST files (and OST), which will be subjected to archive.
For Xopero Cloud users in Endpoint&Server version we enable the backup of mailboxes that are located on the Microsoft Exchange server.
For Xopero Local (XQA and XBR) users with server license it is possible to backup mailboxes that are located on the MS Exchange server.