Effective data loss prevention starts with clarity about what needs protection. Begin by auditing sensitive data - client PII, PHI, payment details, financial records, and intellectual property. Document where this data lives across Microsoft 365 workloads: Exchange, SharePoint, OneDrive, Teams, and managed endpoints.
Microsoft sensitivity labels provide a strong foundation for classification and protection. See Microsoft Purview Sensitivity Labels for core concepts and capabilities.
For SMBs (25–250 employees, like the typical Sourcepass customer segment), start with a clear, minimal taxonomy: Public; Internal; Confidential; Restricted. This structure reduces user confusion and increases labeling accuracy.
Labels can also be used as conditions inside DLP policies so that high-risk data gets stronger guardrails than lower-tier content. This pattern prevents over-blocking while closing the most costly leak paths. Learn more in Use sensitivity labels as a condition in DLP policies.
Identify the highest-risk scenarios:
External emailing of client data
Downloads to unmanaged devices
Guest collaboration in Teams
Transfers to USB or unsanctioned cloud apps
Decide which flows require user justification, which require named user access, and which should be blocked outright. You’ll refine this after an audit-mode pilot.
Start by creating and publishing labels from the Purview portal. Use Create and publish sensitivity labels to build your initial scheme.
DLP policies inspect and govern data across:
Exchange Online
SharePoint
OneDrive
Teams
Policies can detect sensitive information types (health identifiers, credit cards, SSNs), apply encryption, and restrict external sharing. Instead of silent blocks, enable policy tips to coach users in the moment, which improves adoption.
For a full overview of Microsoft Purview DLP capabilities, see Learn about data loss prevention.
Enable Endpoint DLP on Windows and macOS devices to monitor:
Copying to USB
Printing
Uploads to cloud apps
File renaming or movement
Document all exceptions with business justification and align routing of DLP alerts to your IT or SOC operations team.
Deploy in progressive groups:
Security and admins
Finance and legal
HR and client-facing teams
Tenant-wide
Run initial policies in audit mode to observe matches, false positives, and workflow friction. Enforce only after tuning.
Publish a one-page labeling guide
Run 15-minute training sessions for each department
Show examples of encryption and watermarks triggered by labels
Track a small, high-signal KPI set:
% of sensitive documents labeled
Reduction in external sharing of Restricted content
Prevented exfiltration attempts (USB, unsanctioned apps)
Mean time to triage DLP incidents
Secure Score improvements tied to identity and data controls
Leadership dashboards should also include audit evidence tied to label hygiene and DLP policy effectiveness. For taxonomy conditioning evidence, see Sensitivity label as a condition for DLP.
Weekly review in first 30–60 days
Quarterly taxonomy and policy evaluation
Annual review of compliance mapping (2026+)
Celebrate improvements by team and spotlight incidents where policies prevented accidental exposure. Over time, expand into machine learning classifiers and trainable content for higher precision.
Microsoft Purview DLP is a content-aware data loss prevention solution that inspects and protects sensitive information across Microsoft 365 workloads and endpoints, with policy tips, encryption, blocking, and alerting. Learn about data loss prevention.
Yes. Sensitivity labels can be used as conditional logic in DLP policies to enforce stronger guardrails for higher-classified content like Restricted or Confidential data. Sensitivity label as a condition for DLP.
SMBs can create and publish sensitivity labels through the Purview portal using Microsoft’s step-by-step guide for label creation and publishing. Create and publish sensitivity labels.
Yes. Endpoint DLP on Windows and macOS can monitor and restrict activities such as copying files to USB, printing, and uploading to cloud apps, with documented exceptions and alert routing. Learn about data loss prevention.
Key KPIs include: percentage of sensitive files labeled, reduction in external sharing of Restricted content, number of prevented exfiltration attempts (USB or unsanctioned apps), mean incident triage time, and Secure Score improvements tied to identity and data controls.
Most SMBs can deploy and tune Microsoft Purview DLP within weeks, using a ring-based rollout, audit-mode piloting, user enablement, and weekly tuning during the first 30–60 days, followed by quarterly taxonomy review.