Add at least 1 access node for Exchange Online. For high availability (which is recommended for the first full backup), use 2 or more access nodes and extra Azure service accounts. An access node is a virtual machine, a cloud instance, or a physical server that runs backups and other operations.
Before You Begin
You need the following information:
User name and password
From the navigation pane, go to Manage > Servers.
The Servers page appears.
In the upper-right area of the page, click Add server.
The Add server dialog box appears.
Click Select this method to install software packages on your computer.
Enter the necessary information.
From the Select packages list, select OFFICE365, and then click OK.