Most Australian organisations that already pay for Microsoft 365 are also, without quite realising it, paying for a capable data loss prevention engine. Microsoft Purview DLP ships inside the E5 and equivalent security/compliance suites, and it covers the surfaces where data actually leaks for an M365-centric business: Exchange, SharePoint, OneDrive, Teams and, increasingly, the endpoint and the browser. The question Frontrow gets asked is rarely 'does Purview do DLP' — it does. The real question is whether Purview DLP is good enough on its own, or whether the organisation still needs a separate, third-party DLP product sitting alongside it.
It is a fair question, and the honest answer is 'it depends on where your data lives and how it leaves'. For a business whose sensitive content is overwhelmingly inside Microsoft 365, the case for a second DLP is weak. For a business with heavy non-Microsoft data flows — a large Mac fleet, regulated data moving through line-of-business apps, or strict requirements that pre-date the M365 migration — the case is more open. This article walks the decision the way Frontrow walks it with a client.
What Purview DLP genuinely covers well
Purview DLP is strongest exactly where Microsoft owns the pipe. Email through Exchange Online, files in SharePoint and OneDrive, messages and shared files in Teams — these are first-class, mature enforcement points. A policy that blocks an external send containing a run of tax file numbers, or quarantines a SharePoint file shared to a personal address, works reliably and is the same engine Microsoft runs across its own tenants.
Endpoint DLP extends that enforcement to managed Windows devices and, with growing coverage, macOS — controlling copy-to-USB, copy-to-clipboard into unmanaged apps, print, and upload to unsanctioned cloud services. Browser coverage through the Microsoft Edge integration, and increasingly Chrome via the Purview extension, closes the 'paste into a web form' gap that used to be a standard reason to buy a third-party agent. For an organisation whose endpoints are predominantly Windows and whose sensitive data is predominantly in M365, that is a wide moat already paid for.
Where Australian organisations still reach for a standalone DLP
The gaps are real but specific. Purview's enforcement is anchored to the Microsoft estate — the Microsoft 365 services, the Defender for Cloud Apps reverse proxy for sanctioned SaaS, and the managed-endpoint agents. The further your sensitive data sits from that estate, the thinner the coverage gets. The common triggers Frontrow sees for keeping or buying a separate DLP:
- Heavy non-Windows, non-Mac endpoints — Linux engineering fleets, or unmanaged BYOD where you cannot deploy the Purview agent.
- Data egress outside the M365 and major-SaaS path — on-premises file servers, legacy line-of-business apps, direct database extracts, FTP/SFTP, and email gateways that aren't Exchange Online.
- A mature existing DLP investment with tuned rules, an established incident workflow, and analyst muscle memory that would be expensive to rebuild.
- Network-layer or ICAP-style inspection requirements that a SaaS-anchored control isn't designed to satisfy.
- Regulator or contractual obligations that name a specific control architecture pre-dating the cloud move.
Note what is not on that list: 'Purview can't detect Australian identifiers'. It can. Purview ships sensitive information types for tax file numbers, Medicare numbers, passport and driver-licence numbers, and bank account formats, and you can author custom types and trainable classifiers for your own document patterns. 'We need AU-specific detection' is rarely a genuine reason to buy a second product in 2026.
The licensing path: what you actually buy
This is where the buying committee earns its keep, because the answer changes the economics. Purview DLP for the core workloads — Exchange, SharePoint, OneDrive, Teams — is included in Microsoft 365 E5 and in the Microsoft 365 E5 Compliance add-on that sits on top of E3. If you are already on E5, the core DLP is sunk cost; you are choosing whether to also run something else.
Endpoint DLP and the richer classification capabilities are the part that needs E5-tier entitlement. There are two common routes. The first is full Microsoft 365 E5. The second, for organisations that are otherwise happy on E3, is to stack the E5 Compliance add-on (or the narrower Information Protection & Governance add-on) onto the E3 base — which buys the Purview capabilities without paying for the E5 security and voice components you may not need. For frontline/F-tier and education SKUs the entitlements differ again and need checking per-seat.
What Frontrow steers clients away from is paying twice for the same coverage. If you are buying E5 for Copilot, Defender and Entra ID P2 anyway, a third-party DLP covering the same M365 surfaces is mostly redundant spend plus a second console to staff. The standalone DLP earns its line item only when it covers ground Purview structurally cannot reach.
Privacy Act 2026 changes the weighting
The reforms flowing from the Privacy Act review sharpen the case for getting DLP right, whichever product enforces it. Two threads matter most. The Notifiable Data Breaches scheme already obliges organisations to assess and, where the threshold is met, report eligible breaches of personal information — DLP is one of the controls that both reduces the likelihood of such a breach and produces the evidence trail when one is assessed. And the tightening expectations around 'reasonable steps' to secure personal information raise the bar for what a regulator and a board will accept as adequate.
The practical effect is that DLP stops being a nice-to-have for larger organisations and starts being part of demonstrating reasonable steps. The phasing-out of the small-business exemption that has been signalled (and which Frontrow treats as a planning assumption rather than a fixed-date certainty until it is legislated) would pull a large tranche of Australian businesses into scope that previously sat outside it. For those organisations the question is less 'Purview or third-party' and more 'do we have enforced DLP at all' — and for an M365 shop, Purview is the fastest route to a defensible answer.
What we'd actually do
Frontrow's default with an M365-centric Australian client is to start from Purview, not from a product comparison. The sequence is deliberately unglamorous: confirm the E5-tier entitlement is in place (or model the E3-plus-E5-Compliance add-on if it isn't), turn on the built-in AU sensitive information types, and run DLP in simulation mode across Exchange, SharePoint, OneDrive and Teams for a few weeks before any policy moves to enforce. Simulation is the step organisations skip and then regret — it surfaces the false positives and the legitimate business flows that would otherwise generate a flood of blocks on day one.
Endpoint and browser DLP come next, scoped to the devices you actually manage, with USB and unsanctioned-cloud-upload as the first enforced controls because they map cleanly to real exfiltration paths. Only after that baseline is live and tuned does the standalone-DLP question deserve a serious answer — and by then it usually answers itself. If there is meaningful sensitive data leaving through paths Purview can't see, you scope a third-party product to those specific paths rather than buying a second blanket DLP. If there isn't, you have your defensible posture for a fraction of the spend and one console for the team to run.
The trap to avoid is treating this as a single product bake-off. For most Australian mid-market organisations already inside Microsoft 365, the realistic shape of the answer is 'Purview as the platform, a targeted third-party control only where data genuinely lives outside the Microsoft estate' — not two overlapping DLP products competing for the same alerts.