Microsoft 365 is not a backup

Mail works. Teams works. Someone deletes a folder on a Thursday, or a leaver's mailbox is removed because it looked tidy, and the question arrives the following week: can we have it back?

Microsoft keeps copies for its own operations. That is not a promise to you. The recycle bin keeps what it keeps, for as long as it keeps it. A retention policy can hold mail for a legal reason. None of those is a backup you can point at a date and open.

A backup is a separate copy, of the mail and the files, that survives a deleted user, a bad sync, and someone with too much access. It earns the name when a file has been restored on purpose, not when the invoice says the feature is included.

The tenancy around it matters just as much. Entra ID is the list of people and the rules for signing in. If a leaver is still in the address book, they may still be in the files. A shared mailbox is for a team. It is not a place to hide the only copy of a customer's correspondence, and it is not an account with a password taped under a keyboard.

OneDrive and SharePoint are where the files should live. A desktop full of documents, synced or not, is a laptop failure away from a bad week. Known folder move, the setting that takes Desktop, Documents, and Pictures into OneDrive, is worth switching on once you know where the files will land.

If you already pay someone for Microsoft 365, ask them to restore a file while you watch. The answer, and the time it takes, tells you whether you have a backup.