Microsoft Purview is often described as the compliance solution for Microsoft 365. For organizations already standardized on Exchange Online, SharePoint, OneDrive, and Teams, it seems like the natural choice to address governance, risk, and eDiscovery requirements.
But in the real world, compliance is rarely that simple.
Purview is powerful, but it is also purpose-built around a specific operating model. In practice, that means it works best with current, in-platform Microsoft 365 data, assuming content is created, classified, and governed inside Microsoft 365 from day one. That design choice is both its biggest strength and the source of many real-world challenges.
In this post, we review where Microsoft Purview fits in the Microsoft 365 compliance stack, what it does exceptionally well, and where organizations start to struggle, especially when legacy data enters the picture.
To understand Microsoft Purview, it helps to think of it not as a single product, but as a policy and enforcement layer that sits on top of Microsoft 365 services. It does not replace Exchange, SharePoint, or Teams; it governs how data inside those services is classified, retained, discovered, and reviewed.
Microsoft 365 is a unified communications and collaboration platform. Email, documents, chats, meetings, and files all live inside a single ecosystem. Microsoft Purview Compliance exists to govern and defend that ecosystem.
At a high level, Purview brings together three major compliance pillars:
Information Protection & Governance is the foundation of Purview. Its purpose is not just compliance for compliance’s sake, but to help organizations understand the business value and risk profile of their data at scale.
This pillar focuses on understanding what your data is and how long it should exist.
Purview enables organizations to:
When content is born inside Microsoft 365, these controls work extremely well. Classification happens close to creation, and retention logic is applied consistently across mailboxes, Teams, SharePoint, and OneDrive.
Insider Risk Management extends beyond data itself and focuses on user behavior over time. It is designed to uncover patterns that may indicate risk, rather than isolated incidents.
Insider risk capabilities are designed to detect risky or non-compliant behavior by users.
This includes:
These tools are intentionally user-centric, assuming that flagged behavior is current, actionable, and relevant. That assumption becomes important later.
Discovery & Response capabilities are built to support formal legal and regulatory workflows, where defensibility, repeatability, and chain of custody matter as much as search results.
Purview’s discovery tools support legal and regulatory response workflows, including:
These features are optimized for active users and active data, where custodians, mailboxes, and permissions are clearly defined.
Purview’s architecture assumes that data enters the platform in a known state, with active identities, current policies, and modern metadata structures. When those conditions are met, its automation and indexing pipelines operate with very little friction.
Microsoft Purview performs at its best when:
In this scenario, Purview delivers:
For many organizations, this covers the present and future perfectly.
The friction many organizations experience with Purview is often not technical, but conceptual. Each compliance workload answers a different question, and those questions become harder to answer consistently as data ages.
A common misconception is that Purview treats all data equally.
In reality, each compliance area has a different tolerance for context:
These assumptions hold true for modern data, but they start to fracture when older data is introduced.
A policy that works beautifully for today’s Teams messages may produce false positives when applied to a ten-year-old email archive. A discovery workflow designed around active users becomes unwieldy when data no longer maps cleanly to custodians.
Purview isn’t failing here; it’s doing exactly what it was designed to do.
Microsoft Purview is suited if your organization:
For these organizations, Purview can replace multiple point solutions and centralize compliance operations.
Most Purview challenges do not surface immediately. They appear gradually, often months after migrations or policy changes, when operational teams begin to feel the cumulative impact of scale, noise, and performance constraints.
Challenges typically appear when organizations:
At this point, compliance teams often experience:
These issues don’t mean Purview is the wrong tool; they mean it is being asked to solve a different problem than it was designed for.
A Subtle but important distinction; Microsoft Purview is a governance and compliance platform for Microsoft 365. It is not a replacement for legacy archives. Treating it as one can introduce risk, cost, and complexity that compliance teams did not anticipate.
Modern compliance strategies increasingly separate two distinct needs:
Microsoft Purview excels when it is used as intended: governing current, in-platform data with clear custodianship and modern policies. Challenges arise when it is forced to absorb decades of legacy archives, journal data, or non-user-centric content.
This is where complementary platforms become essential.
Cloudficient Expireon provides a dedicated environment for retiring, retaining, and governing legacy email and archive data, without reintroducing noise, performance issues, or policy conflicts into Microsoft 365. It preserves metadata fidelity while allowing legacy information to expire defensibly and cost-effectively.
CaseFusion extends this approach into legal workflows, enabling faster, more targeted eDiscovery by connecting the right data to the right case, without forcing legal teams to search across thousands of irrelevant mailboxes or repositories.
CaseFusion Legal Hold delivers essential, defensible legal hold workflows so organizations can start quickly and expand into the full CaseFusion platform as their needs grow, supporting case-driven preservation and discovery while keeping Microsoft Purview focused on governing live collaboration data.
The result: a compliance architecture that is scalable, defensible, and aligned with how data actually ages, rather than forcing one platform to solve every problem.
If you’re evaluating how to keep Microsoft Purview effective while managing legacy compliance obligations, now is the right time to rethink where different types of data belong.
Microsoft Purview is highly effective for governing and discovering live Microsoft 365 data. Challenges typically arise when organizations attempt to use it as a single system for legacy archives, historic journal data, or non-user-centric content.
Purview assumes data has a modern context, active users, current policies, and consistent metadata. Legacy data often predates these assumptions, which can lead to false positives, slower searches, and operational noise.
Purview is not designed to function as a traditional archive replacement. While it can retain data, it is optimized for governance and discovery within Microsoft 365 rather than long-term, high-volume legacy data management.
Modern collaboration data and legacy archives often benefit from different legal hold approaches. Case-driven legal workflows allow holds to be applied precisely where required without impacting the performance or usability of Microsoft 365.
The most scalable approach is to align tools with data age and purpose, using Microsoft Purview for active collaboration data, while managing legacy content in platforms designed for long-term retention, defensible expiration, and efficient legal review.