How does it works? 

Veeam Backup for Microsoft Office 365 gathers mailbox data from an Exchange organization using Exchange Web Services and PowerShell, and stores it in the repository; data is transferred using SSL. To carry out these operations automatically, an administrator creates and schedules a backup job.

What’s New in v1.5?

The following new features and enhancements are included in Veeam Backup for Microsoft Office 365 version 1.5:

• Distributed, scalable architecture – for enhanced scalability in distributed environments with several Remote Offices/Branch Offices and in service providers’ infrastructures;
• Backup proxies take the workload off the management server, providing flexible throttling policy settings for performance optimization;
• Support for multiple repositories streamlines data backup and restore processes;
• Support for backup and restore of on-premises and hybrid Exchange organizations, allows you to choose from a variety of configurations and usage scenarios and implement those that meet your particular needs;
• Increased performance for restore operations allows for up to 5 times faster restores than in v1.0;
• Restore of multiple datastore mailboxes using Veeam Explorer for Microsoft Exchange simplifies workflow and minimizes workload for restore operators, as well as 1-Click restore of a mailbox to the original location;
• RESTful API and PowerShell cmdlets will be helpful for automation of routine tasks and integration into existing or new portals;
• Support for backup and restore in Microsoft Azure Germany and Microsoft Azure China regions;
• Many enhancements were made to the UI, including main window, wizards, dialogs, and other elements, facilitating administration of the solution.

Lets take a closer look at the Architecture

For enhanced scalability and load balance in distributed environments, Veeam offers a new scalable architecture of Veeam Backup for Office 365, as shown in the figure below:

• Veeam Backup for Microsoft Office 365 server – the central management component that controls licenses and global settings (list of exclusions, email notifications) for the backup proxies. The RestfulAPI service also runs on that server.
• Proxies – the components that perform data backup. A backup proxy can run on a physical or a virtual machine. Initially, the default backup proxy is installed on the Veeam Backup for Microsoft Office 365 server during the product setup, and then users can deploy more proxies to optimize data processing. Each proxy can process one or several Exchange organizations; an organization can be processed by one or several proxies (this means “many-to-many” connections between proxies and organizations).
• Repository – a folder, local or shared (experimental mode), where backup data is stored. Each repository is associated with a backup proxy. Note that you can configure more than one repository for a proxy. For example, a proxy can back up HQ mailboxes to the Repository 11, and remote office mailboxes – to the Repository 12.
• Microsoft Exchange Organization – an Exchange Online, on-premises or hybrid organization whose mailbox database should be backed up. An organization can be processed by one or several backup proxies at a time.
• Job – a collection of configuration settings for organization data backup. Thus, a job represents a backup policy for the organization mailboxes: it prescribes what mailboxes to backup, what data to exclude, what repository storage to use (from those associated with the proxy), and specifies data collection schedule.

Important – If a Veeam Backup for Microsoft Office 365 server fails, its managed proxies will wait for connection to resume for 48 hours. During this period, they will go on with data backup, so that if the server is up and running again in 2 days, all backups will become available via the management console.

What are the Prerequisites?

To provide for backup and restore of Exchange Online items, the following prerequisites are necessary:

Source(s): Veeam Backup for Microsoft Office 365 User Guide