Information Protection: Label It or Block It?

Understanding When to Use Data Loss Prevention versus Sensitivity Labels

Intro to Microsoft Information Protection (MIP)

If your organization’s data estate was an airport, sensitivity labels would be your TSA PreCheck and Data Loss Prevention (DLP) would be the TSA checkpoint.

Both are part of Microsoft Information Protection (MIP), the framework that helps you discover, classify, label, and protect data wherever it lives or travels. Whether that data is sitting in SharePoint, on a USB drive in the parking lot, or attached to an email heading to an external recipient, MIP is what keeps it safe.

Just like TSA PreCheck and the regular security line, Labels and DLP share the same goal: keeping things secure.

• Sensitivity labels are your trusted traveler status. They classify and protect your data ahead of time, giving it instructions that travel with it wherever it goes.

• DLP is the real-time security scan. It watches what your data is doing (like sending, copying, or uploading) and steps in if something risky happens.

  
  

In this post, we’ll walk through when to use each, how they work together, and how to avoid that tug-of-war moment where you’re not sure if you should label it or block it.

What Data Loss Prevention (DLP) Does

Data Loss Prevention (DLP) is all about watching what your data is doing and stepping in when something risky happens. Instead of just focusing on the data’s label or classification, DLP looks at behavior. It watches for patterns that might mean data is being shared, copied, or moved somewhere it shouldn’t be.

Think: Rules + Context + Enforcement = DLP

DLP is the security line every traveler passes through. It scans bags, flags risky items, and decides what can leave the terminal. It doesn’t care who you are or what your status is, it’s focused on keeping the airport safe.

Use DLP When You Need…

• Real-time detection and prevention of risky data actions

• Granular controls over where sensitive data can move

• Visibility and alerts when users try to bypass policy

• Compliance reporting for audits and investigations

What Sensitivity Labels Do

Sensitivity labels are about classifying and protecting information at the data level, instead of the device or network level.

Think of a sensitivity label as a digital tag that tells Microsoft 365, “Hey, this data is sensitive. Treat it differently.” Under the hood, that tag can apply encryption, add watermarks, restrict sharing, or even tie it into a Data Loss Prevention policy for additional flexibility and/or security.

Think: Metadata + Encryption + User Guidance = Sensitivity Labels

If DLP is the TSA officer checking every bag, Sensitivity Labels are your TSA PreCheck status. You’ve already been vetted. The system recognizes you as trusted, and your rules travel with you wherever you go. Labels define what’s sensitive ahead of time, so the system doesn’t have to inspect every action later, it already knows how to handle that content.

Use Sensitivity Labels When You Need…

• Persistent protection that follows the data, not the device

• User empowerment with clear prompts and labeling options

• Rights management like encryption, access limits, and watermarks

• Governance consistency so the same classification ties into DLP, retention, and eDiscovery

Side by Side

Feature	Sensitivity Labels (TSA PreCheck)	DLP (TSA Checkpoint)
Primary Function	Classify & protect	Detect & prevent
Focus	The data itself	User actions on sensitive data
Protection Type	Persistent, travels with file	Contextual, event-based
User Experience	Visible and empowering	Mostly behind the scenes
Best For	Long-term governance & ownership	Preventing real-time data leaks
Example	“Confidential\Internal Only” auto-encrypts document	“Block SSNs leaving company” email rule

Before you go any deeper into the world of Purview, here's a mandatory brain break in the form of a Pine Woods Tree Frog (Hyla femoralis) shared by @ecs_nature in Prince George County, Virginia. These little guys are known for their “machine-gun” call and their incredible ability to blend into pine bark. A nice reminder that not everything about security has to be stressful… sometimes you just need a frog break.

Better Together: The Full Security Checkpoint

Sensitivity labels and DLP are strongest when they work together.

Think of it like going through the airport when you have TSA PreCheck. You still go through security, but the process is smoother because the system already knows who you are. Your identity (the Sensitivity Label) helps security (DLP) make faster, smarter decisions about what needs extra attention. One defines what is sensitive; the other enforces how that sensitive data can move.

When labels and DLP work hand in hand, you get both proactive protection and reactive enforcement:

• A document labeled “Highly Confidential” can automatically trigger DLP to block external sharing.

• A file labeled “Public” can pass through without unnecessary friction.

• DLP can even use label metadata to make policy decisions on the fly.

Together, they make security feel less like a wall and more like a smart filter that adjusts based on what it already knows about your data.

Sensitivity labels build trust into the data. DLP enforces trust around the data.

When you use both, you’re creating a consistent, intelligent protection framework that follows your data everywhere it goes.

Practical Guidance

Implementing Microsoft Purview’s DLP and Sensitivity Labels can feel overwhelming, but with the right approach and expert support, you can build a data protection program that’s both robust and user-friendly.

Here’s how to get started:

1. Assess Your Data Landscape

• Action: Inventory your data locations (SharePoint, OneDrive, Exchange, endpoints, etc.) and identify where sensitive information lives and moves.

2. Define and Align Policies

• Action: Develop clear classification schemes and DLP policies that reflect your organization’s regulatory, contractual, and business requirements.

3. Deploy Sensitivity Labels

• Action: Roll out sensitivity labels to classify and protect data at the source. Start with pilot groups, gather feedback, and iterate.

4. Implement DLP Policies

• Action: Configure DLP to monitor and control risky actions in real time, such as sharing sensitive data externally or copying to USB.

5. Integrate and Optimize

• Action: Ensure sensitivity labels and DLP work together by using label metadata to drive DLP decisions and automate protection.