Microsoft Purview: A Practical Guide to Data Security and Compliance

What Is Microsoft Purview?

Microsoft Purview is the unified platform for data governance, data security, and compliance across your Microsoft 365 environment and beyond. It consolidates what were previously separate products — Microsoft Information Protection, Microsoft Compliance Manager, Azure Purview — into a single, integrated experience.

For organizations navigating increasing regulatory pressure and data sprawl, Purview provides the tools to discover, classify, protect, and govern data wherever it lives.

Core Capabilities

Data Classification

Before you can protect data, you need to know what you have. Purview classifies data using three mechanisms:

Sensitive Information Types (SITs) — built-in and custom pattern detectors:

• Over 300 built-in SITs detect patterns like credit card numbers, passport numbers, medical record identifiers, and financial account numbers
• Custom SITs let you define patterns unique to your organization (employee IDs, internal project codes, proprietary data formats)
• SITs use a combination of regular expressions, keyword dictionaries, and proximity rules to reduce false positives

Trainable Classifiers — machine learning models trained on your data:

• Pre-trained classifiers detect common document types (resumes, source code, financial statements, legal documents)
• Custom trainable classifiers learn from sample documents you provide — feed it 50 examples of your contract format and it will find all similar contracts across your tenant

Exact Data Match (EDM) — for structured sensitive data:

• Upload a table of known sensitive values (customer account numbers, patient IDs) and Purview will detect exact matches in documents and emails
• More accurate than pattern matching because it detects your actual data, not just data that looks similar

Sensitivity Labels

Sensitivity labels are the primary mechanism for classifying and protecting content:

• Visual markings — headers, footers, and watermarks indicate classification
• Encryption — restrict who can open, edit, print, or forward a document
• Access expiration — set a date after which external users lose access
• Container labels — apply labels to Teams, SharePoint sites, and Microsoft 365 groups to control guest access, sharing settings, and unmanaged device access
• Auto-labeling policies — automatically apply labels based on content inspection, with simulation mode for tuning before enforcement

Data Loss Prevention (DLP)

DLP policies prevent sensitive data from leaving your organization through unauthorized channels:

• Exchange Online — scan outgoing emails and attachments for sensitive content; block, quarantine, or notify
• SharePoint and OneDrive — detect sensitive files and restrict external sharing
• Teams — scan messages and shared files in real time
• Endpoints — control copy-to-USB, print, upload-to-cloud, and clipboard actions on Windows and macOS devices
• Power BI — prevent export of sensitive data from reports and dashboards

DLP policies generate alerts in the Purview compliance portal, where administrators can investigate and remediate incidents.

Insider Risk Management

Insider threats — whether malicious or accidental — are one of the hardest security challenges. Purview Insider Risk Management detects risky behavior patterns:

• Data theft by departing employees — detects unusual download or sharing activity correlated with HR departure signals
• Data leaks — identifies users sharing sensitive content externally at abnormal rates
• Security policy violations — detects users disabling security controls, accessing restricted content, or circumventing DLP policies
• Privacy by design — user identities are pseudonymized by default; only authorized investigators can see real names after escalation

eDiscovery

When legal hold or investigation requirements arise, Purview eDiscovery provides:

• Content search — search across Exchange, SharePoint, OneDrive, and Teams for relevant content
• Legal holds — preserve content in place so it cannot be deleted or modified
• Review sets — collect, deduplicate, and review responsive content with AI-assisted relevance scoring
• Export — produce content in standard formats for external legal counsel
• eDiscovery Premium — advanced capabilities including conversation threading, near-duplicate detection, and predictive coding

Compliance Manager

Compliance Manager provides a risk-based compliance score and actionable recommendations:

• Pre-built assessments for major regulations (GDPR, HIPAA, SOC 2, ISO 27001, CCPA)
• Improvement actions — step-by-step guidance for each control, with links to the relevant Purview settings
• Continuous monitoring — your compliance score updates automatically as you implement controls
• Custom assessments — create assessments for industry-specific or internal compliance requirements

Implementation Priorities

Organizations new to Purview should implement capabilities in this order:

1. Data classification — run Content Explorer to understand what sensitive data exists and where
2. Sensitivity labels — deploy a simple label taxonomy (4-5 labels) with manual labeling first
3. DLP policies — start in test mode for Exchange and SharePoint; tune before enforcing
4. Retention policies — apply basic retention to email and SharePoint to prevent premature deletion
5. Auto-labeling — once manual labeling is adopted, add auto-labeling for the highest-risk content
6. Insider risk — deploy after foundational controls are in place
7. eDiscovery — configure when a legal or regulatory event requires it

Licensing

Purview capabilities are spread across multiple license tiers:

• Microsoft 365 E3 — includes basic sensitivity labels, manual classification, basic DLP, and content search
• Microsoft 365 E5 — adds auto-labeling, advanced DLP (endpoint and Teams), Insider Risk Management, eDiscovery Premium, and Compliance Manager premium assessments
• Add-on licenses — individual Purview capabilities can be added to E3 without upgrading to E5

Evaluate which capabilities you need before committing to a licensing tier.

Get Started with Purview

Al Rafay Consulting helps organizations implement Microsoft Purview across their Microsoft 365 environment. From initial data assessment through policy enforcement, we ensure your compliance and security posture is strong without disrupting daily productivity.

Schedule a Purview consultation