Office 365 Email Archiving

What is Office 365 Email Archiving?

Office 365 email archiving uses an online archive mailbox as a secondary storage location automatically associated with a user’s email account in Microsoft 365. This archive exists alongside the primary inbox and is designed to store messages long-term without affecting day-to-day email performance or increasing active mailbox size unnecessarily.

Users can access archived messages through familiar interfaces such as the Outlook online archive, allowing them to search historical communications and old emails without restoring data back into active storage.

Each Office 365 mailbox includes this archive capability, enabling organizations to preserve historical communications while maintaining a streamlined inbox experience in Microsoft Outlook.

How retention policies power email archiving

Retention policies control how and when messages are moved into an archive mailbox based on defined rules, such as message age or classification. These policies automate mailbox archiving, reducing the need for manual sorting or user intervention.

Once configured, retention rules can archive emails automatically, ensuring consistency across the organization and reducing reliance on individual user behavior. Messages moved into the archive remain searchable and intact as archived content, supporting compliance and discovery requirements.

By shifting old emails out of active storage, retention policies help organizations manage mailbox size growth while preserving access to business-critical communications associated with each Office 365 account.

Improve Office 365 archiving with Mimecast

While the Microsoft Office 365 cloud email solution offers tremendous benefits in terms of lower costs, greater scalability and reduced complexity, insufficient Office365 archive capabilities keep many organizations from migrating to this popular productivity solution.

Robust email archiving and search capabilities are essential to user productivity, mail security and legal and compliance requirements. Office365 archive tools, however, fall short when it comes to e-discovery and compliance capabilities. Beyond storage gaps, Microsoft’s batch-processing architecture can delay new compliance policies by 24–48 hours for some connected data sources, creating windows where policy violations and data events may go undetected. Office365 archiving features don't enable easy migration and management of legacy email archives. And because it stores all copies of emails within the same architecture, Office 365 creates a single-point-of-failure when it comes to redundancy and safeguarding email data.

Mimecast Aware offers a powerful alternative to support Office365 archive capabilities, enabling organizations to move to Office 365 more readily. As an independent, cloud-based archive, Mimecast provides stronger resilience, cross-platform visibility, and faster access to the data compliance teams actually need. In real-world enterprise testing, Mimecast completed eDiscovery tasks 6.7x faster than Microsoft Purview, reducing what took Microsoft 8 hours to approximately 1 hour 12 minutes. Mimecast’s purpose-built AI, trained specifically on enterprise communications, improves search accuracy and sentiment analysis so reviewers can find the most relevant messages faster instead of sorting through excessive false positives. 

Modern archiving must also go beyond email. Mimecast captures and preserves communications across Microsoft Teams, Slack, Zoom, and other platforms in real time through native API integrations, maintaining message context, edit histories, and conversation threading. Microsoft’s approach to third-party platforms relies more heavily on complex connectors that can introduce delays and strip away valuable metadata.  By augmenting Office365 archive capabilities with Mimecast Aware, Office 365 can become the all-around productivity solution organizations needed to be.

Explore Mimecast Governance & Compliance

Easily manage your Office 365 archive

Mimecast augments your Office365 archive with governance and compliance capabilities that enable you to:

• Complete eDiscovery tasks significantly faster, with Mimecast completing eDiscovery work 6.7x faster than Microsoft Purview in real-world enterprise testing.
• Employ flexible, policy-driven retention at the organization, group, mailbox or published retention folder.
• Comprehensive support for e-discovery, compliance and litigation requests, including legal hold, case management and data export.
• Improve archive security with encrypted, secure storage in multiple data centers, with triplicate copies for built-in redundancy.
• Preserve complete forensic context, including edit histories, deleted messages, and full conversation threads, so reviewers have the full picture during compliance investigations.
• Use predictable, per-user pricing regardless of data volume or platform, avoiding Microsoft’s pay-as-you-go costs for third-party data ingestion that can scale unexpectedly as communication history grows.

Benefits of Office 365 Email Archiving

Mimecast Aware Governance & Compliance Suite provides superior tools for migrating email data to your Office 365 archive.With Mimecast's solution for migrating to Office 365 from Exchange or from other platforms, you can rapidly ingest historical email archives into the Mimecast cloud where it becomes easily accessible to users and administrators. 

Because Mimecast supports cross-platform archiving and defensible search across email and collaboration tools, it gives compliance teams a more complete and usable record than an email-only archive model. Mimecast's Office 365 Email Archiving solution stores email data within geographically-defined regions with tamper-resistant chains of custody, providing a secure encrypted archive with a 100% platform availability SLA.