In a surprising number of Microsoft 365 tenants I review, Purview information protection is either missing entirely or was bolted on as an afterthought. Even with E5 licenses in place, sensitivity labels are often barely configured or hopelessly overengineered. The feature set, from custom info types and auto-labeling to DLP, can be overwhelming. In my experience the best results come from keeping things simple and pragmatic, especially at the start. If you want classification and protection that the business actually uses, less really is more.

Four clear labels beat a complex taxonomy

The first question is always how many sensitivity labels we actually need. In practice, four usually do the job: Public, Internal, Confidential, and Highly Confidential. People understand them right away, and they map neatly to typical business protection needs. I've seen teams tempted to invent department-specific labels, but that only creates confusion. It's far better to start broad and keep things clear, then refine later if you really need more granularity. The label names should make sense to IT and business users alike. Labels that need a manual to interpret never gain traction.

Auto-labeling should start with a few simple rules

Auto-labeling is where labeling starts to pay off. Microsoft Purview ships with a large set of built-in sensitive information types, such as credit card numbers or national IDs, which you can use as triggers. At the beginning I keep auto-labeling rules minimal and run them in simulation mode. Think of it as a dress rehearsal: you see what would happen without anything being enforced. If needed, you can build custom info types (for example with regex for internal numbers). The details are in Microsoft's sensitivity labels documentation for Purview.

Before you let labels auto-encrypt documents or emails, take a close look at how your data is distributed. Content Explorer and Activity Explorer in Purview are very useful here, because they show where sensitive data lives and how it's handled. For a quick overview of the labels in use, I often run this PowerShell snippet:

Get-Label | Select-Object Name, ContentType, IsEncrypted

Activity Explorer in particular tells you a lot about real-world data flows before you switch policies on for real.

DLP policies always run in test mode before enforcement

Data Loss Prevention (DLP) stops sensitive data from leaking out, provided it's set up properly. In nearly all my projects I start DLP policies in “test with notifications” mode. That way I see potential issues without breaking user workflows or alarming people with false positives. Microsoft's DLP documentation contains useful policy patterns. I only switch to active enforcement once I understand the data flows and risk areas, and even then I do it step by step.

Pro tip: Start with a small number of clear labels and a manageable set of auto-labeling rules. Users accept the system much more readily when they aren't flooded with choices or warning messages.

The business needs to be involved from the start

A common mistake is treating information protection as a purely IT project. Without input from the business, labels stay abstract and end up ignored or used incorrectly. I bring business units in early. Workshops work well for collecting real use cases and agreeing on what each label actually means. That's what makes a taxonomy work in daily practice and not just in policy documents. All the encryption in the world won't help if people don't understand when “Highly Confidential” is really required. Some of the best process improvements for labeling and DLP have come out of exactly these conversations.

Classification, encryption and DLP work as one chain

To make the path from classification to protection and monitoring concrete, I've drawn a simple diagram. It shows how a document moves through each stage of the Purview protection process:

flowchart TD
    A["Document created"] --> B["Label applied"]
    B --> C["Auto-labeling scans info types"]
    C --> D["Label may change"]
    D --> E["Label triggers encryption"]
    E --> F["DLP policy checks sharing"]
    F --> G["Activity monitored"]

Figure: Document protection workflow in Microsoft Purview

As the diagram shows, a label is much more than a tag. It drives encryption, sharing permissions and even compliance boundaries. Automatic detection of info types is what lets this scale across the business while keeping the manual effort down.

I treat classification as a long process rather than a sprint

Many teams expect instant results when they roll out Purview Information Protection. In reality, effective classification and protection take time and several iterations. Review your taxonomy and rules regularly with the business owners, and use the analysis tools to find blind spots. The prettiest policies don't count for much; what matters is what people actually use. Start small, collect feedback and keep users in the loop. Over time you'll get better protection with less friction.