Microsoft 365 · Guide
Does Microsoft 365 back up your email and files?
Microsoft keeps the service running and lets you recover deleted items for a limited time. That is not the same as a backup you control, and the gap matters when someone deletes, overwrites or encrypts something you only notice later.
Updated · Nexus Digital Ireland
The short answer
Microsoft protects its service against hardware failures and disasters in its data centres. It does not keep a long-term, point-in-time copy of your mailboxes and files that you can restore from whenever you like. Microsoft describes this as a shared responsibility: it runs the service, and you are responsible for your data and how long you need to keep it.
What Microsoft 365 keeps, and for how long
- Deleted email
- Recoverable for 14 days by default after it leaves Deleted Items, which an admin can extend to 30 days.
- OneDrive and SharePoint files
- Deleted files stay in the recycle bins for up to 93 days, and OneDrive can be restored to an earlier point within the last 30 days.
- Version history
- Files in OneDrive and SharePoint keep previous versions, which helps when a file is overwritten.
- Deleted users
- A deleted user's account and mailbox can be restored for 30 days. Their OneDrive is kept for 30 days by default, which an admin can change.
- Retention policies and holds
- Compliance features that keep data for set periods. They help with legal and audit needs but are not designed for quick restores.
These are Microsoft's published defaults when this guide was updated. Settings in your account may differ.
When that is not enough
- Something is deleted and nobody notices until after the recovery window.
- A leaver's mailbox and OneDrive are removed with their licence.
- Ransomware on a laptop encrypts synced files and the changes sync to OneDrive.
- An attacker or an unhappy employee deletes data deliberately.
- A customer, insurer or auditor asks you to show records from years ago.
- Someone needs a whole SharePoint site or mailbox restored as it was on a given date.
Your options
- Microsoft 365 Backup
- Microsoft's own paid backup service for Exchange, OneDrive and SharePoint, billed by storage used.
- Third-party backup tools
- Services that copy Microsoft 365 data to separate storage, often with longer retention and simple restores.
- Retention policies
- Useful alongside a backup for keeping records for a set period, but not a replacement for one.
Whichever you choose, the test is the same: restore something real and time it. A backup nobody has restored from is an assumption, not a plan.
Questions to decide what you need
- What must you keep?Customer records, contracts, finance mailboxes, project files.
- For how long?Revenue, customer contracts, insurers and ISO audits may each expect records to be kept for years.
- How quickly must you recover?An hour, a day or a week without each system.
- Who restores, and how?Know who to call and test it before you need it.
How Nexus helps with Microsoft 365 backup
Nexus Digital reviews what your business keeps, sets up a backup that fits, and proves it with a real restore test.
- A review of what Microsoft 365 already keeps for you and where the gaps are.
- Backup set up for the mailboxes, OneDrives and SharePoint sites that matter.
- A timed restore test and written results, ready for insurers, customers or audits.
Questions
Does Microsoft back up Office 365 email?
Not as a long-term backup. Deleted email can be recovered for 14 days by default, and up to 30 if an admin extends it. After that it is gone unless you have a separate backup or retention policy.
Is OneDrive a backup?
OneDrive syncs files, so deleting or encrypting a file on your computer also changes it in OneDrive. Version history and the recycle bin help for a limited time, but OneDrive is not an independent backup.
What happens to a leaver's email when we remove their licence?
The mailbox is kept for 30 days and then deleted. Convert it to a shared mailbox or back it up first if you need to keep it.
Does Microsoft sell its own Microsoft 365 backup?
Yes. Microsoft 365 Backup is a paid service billed by the amount of data protected. Third-party backup services are also available.
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