Retention policies vs backups in Microsoft 365: What’s the difference?

Microsoft 365 is now the operational backbone of most organizations. Email, collaboration, file sharing, communication and decision-making all rely on Exchange Online, OneDrive, SharePoint and Teams. Yet despite this dependency, one misconception remains persistent across IT teams and service providers: 

Many organizations believe Microsoft 365 retention policies function as a backup strategy. They do not. 

Retention, versioning, recycle bins and labels were designed for content lifecycle management and basic governance — not point-in-time recovery, cyber resilience or long-term preservation. When data is deleted past its retention threshold or purged due to misconfiguration, there might be no way to recover it natively. 

This article clarifies the critical differences between retention and backup, explains Microsoft’s own Shared Responsibility Model, and outlines how organizations can achieve complete M365 protection with Acronis Cyber Protect Cloud. 

Retention policies play an important role in managing how long content remains in the system after it is modified or deleted. They support compliance, help organizations meet basic governance requirements, and reduce accidental short-term data loss. But they are not designed to function as disaster recovery or business continuity mechanisms. 

What retention policies do: 

• Define how long items remain available after deletion. 

• Govern deletion behavior for content in Exchange, SharePoint and OneDrive. 

• Support content lifecycle and compliance use cases. 

• Assist with short-term recovery from user mistakes. 

Most native retention windows fall between 30 and 90 days, depending on the workload and configuration. After the retention period expires, Microsoft permanently removes the content from its systems. 

Retention keeps data available temporarily. Backup ensures recoverability indefinitely. 

Microsoft is explicit about the line between what they protect and what customers must protect. Their Shared Responsibility Model states: 

Microsoft: 

• Maintains the platform 

• Ensures uptime and service continuity 

• Provides security of the underlying infrastructure 

• Manages physical data centers 

Customers: 

• Protect their own content 

• Manage retention and data governance 

• Mitigate internal threats and accidental deletion 

• Back up their M365 data 

Microsoft’s documentation includes this unambiguous directive: 

“We recommend that you regularly back up your content and data that you store on the services or store using third-party apps and services.” 

The meaning is clear: Microsoft provides the platform. Customers — or their MSPs — are responsible for protecting the data. 

This applies universally across: 

• Exchange Online 

• SharePoint Online 

• OneDrive for Business 

• Microsoft Teams 

• Microsoft 365 Groups 

Without independent backup, organizations remain exposed to data loss resulting from deletion, ransomware, retention configuration errors or license changes. 

A true backup solution is fundamentally different from retention. It creates a separate, secured, restorable copy of Microsoft 365 data that exists independently of the production environment. 

1. Point-in-time recovery 

Backups allow organizations to restore systems to a precise historical state — a critical requirement after ransomware attacks, accidental deletions or major misconfigurations. 

Retention cannot roll back an entire mailbox, site or Teams workspace to a specific point in time. 

2. Long-term retention for governance 

Many industries must preserve data for three, seven or even 10+ years. Microsoft’s built-in tools cannot meet these requirements unless heavily customized. 

Backup provides policy-driven, compliance-aligned retention without depending on the Microsoft 365 tenant configuration. 

3. Granular recovery across workloads 

Backup supports restoration of: 

• Individual emails 

• Mailboxes and folders 

• SharePoint sites and lists 

• OneDrive files and folders 

• Teams messages, channels, files and meeting content 

Retention cannot restore the full state of data once purged. 

4. Protection from ransomware and malicious actions 

Backup with immutability prevents attackers from encrypting or altering stored data, ensuring organizations always have a clean recovery point. 

5. Off-platform, independent protection 

If a Microsoft 365 tenant becomes compromised or unavailable, backup data in an independent platform remains recoverable. 

Retention lives inside Microsoft’s environment. Backup lives outside it where it cannot be altered or deleted by a compromised account. 

Retention solves administrative and compliance challenges but does not protect against the full spectrum of modern operational risks. 

Below are the six high-risk scenarios where reliance on retention alone leads to permanent data loss. 

1. Delayed discovery of deleted data 

Most organizations do not notice missing files, chats or messages immediately. Data requests often arise months later, during: 

• Audits 

• Legal discovery 

• HR investigations 

• Regulatory reviews 

By that point, retention windows (30–93 days for many workloads) have expired, leaving no recovery option. 

2. Retention misconfigurations or policy conflicts 

Retention configurations in Microsoft 365 can be complex. Common failure modes include: 

• Incorrect policy priorities 

• Label mismatches 

• Conflicting delete / retain actions 

• Policies applied to the wrong users or sites 

• Content excluded due to license or group changes 

A misconfigured policy may silently purge data. 

3. Ransomware and malicious encryption 

Retention protects deleted items — not encrypted ones. If ransomware encrypts mailbox content, SharePoint files or OneDrive data, retention preserves the encrypted version. 

Only backup allows restoration from a clean, unencrypted point. 

4. Insider threats or accidental mass deletion 

Users with access can: 

• Delete entire folders 

• Purge mailbox items 

• Remove Teams channels or files 

• Overwrite large sets of data 

A malicious insider who double-deletes content from recycle bins eliminates all remaining native recovery options. 

5. Tenant compromise 

If an attacker gains administrative access: 

• Retention policies can be altered 

• Items can be permanently deleted 

• Version history can be overwritten 

• Mailboxes and sites can be wiped 

Backup stored in an isolated, immutable location is the only reliable safeguard. 

6. Regulatory retention requirements exceed Microsoft defaults 

Frameworks such as: 

• GDPR 

• HIPAA 

• FINRA 

• SEC Rule 17a-4 

• ISO 27001 

Often mandate multi-year data retention. Microsoft’s default retention does not cover these timelines. 

Organizations need sovereign control over retention periods — independent of cloud provider settings. 

Acronis Cyber Protect Cloud is designed to provide the complete, compliance-aligned Microsoft 365 protection that native retention cannot achieve. 

Acronis backs up: 

• Exchange Online 

• SharePoint Online 

• OneDrive for Business 

• Microsoft Teams 

Including granular items within each workload. 

Restore: 

• A single email 

• A specific SharePoint file version 

• A full OneDrive account 

• A Teams channel or message thread 

• A mailbox or site as of any historical date 

This ensures fast recovery after accidental deletions, ransomware, or configuration issues. 

Acronis enables: 

• Immutability to prevent tampering 

• Encryption in transit and at rest 

• Segregated storage independent of Microsoft 

This protects backup data even if the Microsoft 365 tenant is compromised. 

Acronis supports retention policies of: 

• One year 

• Three years 

• Seven years 

• 10+ years (custom) 

This aligns with regulatory expectations across finance, healthcare, legal, government and enterprise IT. 

Acronis Cyber Protect Cloud includes: 

• Multitenant management 

• Automated onboarding 

• Predefined backup policies 

• Centralized monitoring and reporting 

• Usage-based billing and service packaging 

MSPs can deliver standardized M365 protection as a core offering. 

Acronis unifies backup with cyber protection tools, including: 

• Anti-ransomware technology 

• Anomaly detection 

• Vulnerability assessment 

• Forensic data collection 

This ensures organizations do not just back up data — they protect its integrity. 

To achieve maturity in Microsoft 365 resilience, IT leaders and MSPs should adopt a strategy that combines Microsoft retention with independent backup. 

Begin by mapping Microsoft’s Shared Responsibility Model to your internal or client environment. 

Retention helps with compliance and basic lifecycle management, but is not sufficient for continuity or recovery. 

Teams, SharePoint, OneDrive and Groups hold critical operational knowledge that must be protected. 

Quarterly restore testing validates: 

• SLA compliance 

• Data integrity 

• RTO expectations 

• Disaster recovery readiness 

Ensure backups cannot be modified or deleted, especially during cyberattacks. 

Review compliance retention timelines annually 

Update backup policies based on: 

• Emerging regulations 

• Contractual obligations 

• Internal risk assessments 

Make Microsoft 365 backup a standard layer in all service plans to reduce liability and strengthen client resilience. 

Retention plays an important role in Microsoft 365, but it is not a substitute for backup. Retention governs how long data remains in the system before deletion. Backup ensures that data is recoverable no matter what. 

Microsoft’s own guidance makes this distinction unmistakably clear: 

“We recommend that you regularly back up your content and data…” 

Acronis Cyber Protect Cloud delivers the complete protection required for modern Microsoft 365 environments: 

• Independent, point-in-time backups 

• Granular restores across all workloads 

• Immutable, secure storage 

• Long-term compliance retention 

• MSP-ready management and automation 

Learn how Acronis Cyber Protect Cloud ensures your Microsoft 365 data remains protected, compliant and recoverable — no matter what.