A departing sales director’s licence is removed on her last day. Three months later a contract dispute arises, and the legal team asks for her email from the previous year. The mailbox is gone. So is the assumption that Microsoft had been keeping a copy all along.
Microsoft 365 is not a backup service. Microsoft is responsible for keeping the platform running and its infrastructure resilient. Protecting the content inside it, beyond limited built-in retention, falls to the customer. That division is why third-party tools such as Veeam Backup for Microsoft 365 exist at all.
The Assumption Inside Every Subscription
Cloud software changes where data lives, and it is easy to assume it also changes who is responsible for it. Email once sat on a server in the office, and someone in IT backed it up. When mail moved to the cloud, the server disappeared from view. Many organisations quietly dropped the backup along with it.
Microsoft describes its approach through a shared responsibility model. Read carefully, the model draws a firm line between the service and the data.
Where Built-In Retention Falls Short
Microsoft 365 does include recycle bins, version history and configurable retention policies, and they are genuinely useful. They are also designed for a different job. Recycle bins empty after a fixed period. Retention policies preserve content for compliance, but they are not built for quickly restoring an entire mailbox or site to how it looked last Tuesday.
A dedicated backup keeps independent, point-in-time copies outside the tenant. Veeam and other vendors in this space store those copies separately from Microsoft’s environment, so a problem inside the tenant does not reach them.
Some organisations start with Exchange and OneDrive, where everyday data loss is most common. They extend protection to SharePoint and Teams later.
Reading the Agreement Differently
A subscription buys access to a service that rarely goes down. It does not buy an archive of every decision users and administrators have made. The sales director’s mailbox was lost because nobody decided to keep it.
