CIO Playbook: Maximising Security & Compliance with Microsoft 365 E5 Add-ons

Microsoft 365 E5 Security Add-on

The E5 Security add-on is a per-user licence providing Microsoft's top-tier security tools, layered on top of M365 E3. It delivers the advanced threat protection and identity security features of a full E5 plan without forcing you to pay for unrelated extras like telephony or analytics. For an overview of Microsoft's broader licensing landscape, see our Microsoft Licensing Knowledge Hub.

🛡️ What's Included: The Defender XDR Suite

Microsoft Entra ID Premium P2 — Risk-based conditional access, Identity Protection, Privileged Identity Management (PIM) for just-in-time admin access. Defender for Endpoint Plan 2 — Full EDR with behaviour-based threat detection, automated investigation/remediation, vulnerability management. Defender for Office 365 Plan 2 — Safe Links, Safe Attachments, AI phishing detection, attack simulation, Threat Explorer. Defender for Identity — On-prem AD threat monitoring (pass-the-ticket, lateral movement, domain compromise). Defender for Cloud Apps — CASB for shadow IT detection, conditional access to cloud apps, data exfiltration protection.

These four Defender components work together as an Extended Detection and Response (XDR) suite, sharing signals to correlate threats across email, endpoints, identities, and cloud applications.

What's NOT included: E5 Security does not include compliance solutions (eDiscovery, Insider Risk, data governance — those are in the separate E5 Compliance/Purview add-on). It also excludes Teams Phone System, Power BI, and Intune (Intune comes with EMS E3, which is already part of M365 E3). The idea: enhance security without paying for non-security E5 components.

Enterprise Mobility + Security (EMS) E5

EMS E5 is a per-user bundle focused on advanced identity, device, and information protection. It includes EMS E3 components (Azure AD P1, Intune, AIP P1) plus advanced capabilities. Often used with Office 365 E3 or M365 E3 to strengthen identity security and protect information across devices.

🔐 What's Included: Identity & Data Protection

Azure AD Premium P2 — Full identity security: PIM, Identity Protection, access reviews (same as in E5 Security). Azure Information Protection (AIP) P2 — Automatic classification and encryption of sensitive files, user-defined sensitivity labels with protection, document tracking. Defender for Identity — On-prem AD threat monitoring (same as E5 Security). Defender for Cloud Apps — CASB solution for shadow IT and cloud app control (same as E5 Security). Microsoft Intune — Mobile device and application management for enforcing device compliance, deploying apps, remote wipe.

E5 Security vs EMS E5: Key Differences

Component	M365 E5 Security	EMS E5
Entra ID Premium P2	✅ Included	✅ Included
Defender for Identity	✅ Included	✅ Included
Defender for Cloud Apps (CASB)	✅ Included	✅ Included
Defender for Endpoint Plan 2 (EDR)	✅ Included	❌ Not included
Defender for Office 365 Plan 2 (Email)	✅ Included	❌ Not included
Azure Information Protection P2	❌ Not included	✅ Included
Microsoft Intune	❌ Not included	✅ Included
Best For	Full Defender XDR suite (endpoint + email + identity + cloud)	Identity governance + data protection + device management
Relative Cost	Higher (includes expensive EDR + email protection)	Lower (focused on identity + data + mobility)

Choosing between them: E5 Security provides the full Microsoft Defender XDR suite — best if you want Microsoft's advanced threat protection across endpoints, email, identity, and cloud. EMS E5 provides identity governance and data protection — useful if you're handling endpoint or email security separately (perhaps via a third-party EDR) or aren't ready to upgrade those for all users. Many CIOs choose M365 E3 as standard, then supplement with a few E5 Security and/or EMS E5 licences for those requiring additional protection. For context on Microsoft EA optimisation, see our Microsoft EA Renewal Negotiations Playbook.

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Microsoft Purview and E5 Compliance Add-on

Microsoft Purview is the branding for an integrated set of data protection, governance, and compliance tools. The E5 Compliance add-on unlocks all advanced compliance features of M365 E5 — essential for highly regulated or security-conscious organisations. For more on Microsoft compliance licensing, see our Microsoft Licensing Knowledge Hub.

📋 What's Included: Advanced Compliance Suite

Purview Information Protection (AIP P2) — Auto-labelling based on content using ML or predefined rules, trainable classifiers. Advanced DLP — Endpoint DLP extending policies to Windows/macOS endpoints, Teams chat DLP, integration with Defender for Cloud Apps. Insider Risk Management — Identifies risky user activities (data theft, policy violations) using signals across M365. Communication Compliance — Monitors Teams chats and emails for policy violations (harassment, insider trading). Advanced eDiscovery (Premium) — End-to-end legal discovery workflow with case management, legal hold notifications, analytics (near-duplicates, themes). Advanced Audit — 1-year audit log retention (vs 90 days in E3), high-value event auditing. Customer Lockbox — Explicit control over Microsoft support access to your content. Privileged Access Management — Approve/restrict admin tasks in Exchange and SharePoint.

Tenant-wide licensing consideration: For some Purview features (retention auto-labelling, legal holds), all users whose data is governed may require licensing. Microsoft's guidance: if a user benefits from or is subject to a feature, they should be licensed. A retention policy scanning all SharePoint sites arguably requires all those sites' users to be licensed. Work with your licensing specialist to ensure compliance when rolling out Purview features.

Allocating Premium Licences by Role

A cost-effective strategy involves assigning different licence levels based on risk profile, job function, and data access. The goal: "E3 for most, E5 for few" — maximise protection where it's needed without overspending on low-risk users.

👔 Executives and VIPs

Senior leadership are high-value targets for spear phishing and account compromise, and handle the most sensitive data. Equip them with E5 Security for maximum protection — Entra ID P2, full Defender suite, Defender for Office 365 P2 for advanced phishing protection. On the compliance side, consider E5 Compliance if they handle regulated information or are likely subject to legal inquiries. CEOs and board members often have communications retained for legal purposes or handle M&A confidential information. Recommendation: Full E5 treatment for security and compliance.

🔑 IT Administrators and Security Personnel

Anyone with elevated access (tenant admins, global admins, domain admins, security analysts) should have E5 Security or EMS E5. These are "keys to the kingdom" accounts — you need PIM for just-in-time access, risk-based MFA, Defender for Identity monitoring, and Defender for Cloud Apps for admin activity oversight. Microsoft recommends giving admin accounts an E5 licence solely for security benefits. Give E5 Compliance to those who administer or review Insider Risk/eDiscovery cases. Recommendation: All privileged users receive E5 Security; compliance admins get E5 Compliance.

⚖️ Legal and Compliance Officers

Prime candidates for E5 Compliance. They need Advanced eDiscovery (legal cases, content searches, holds, audit logs), Communication Compliance, and Purview management tools. By assigning E5 Compliance, they can perform in-house discovery rather than outsourcing. Note: if legal places holds on many users' mailboxes, those target users should ideally have E5 Compliance as well. Recommendation: E5 Compliance for legal/compliance personnel; adequate baseline security for their accounts.

👥 HR and Insider Risk Team

HR managers and insider threat investigators should receive E5 Compliance for Insider Risk Management and Communication Compliance. Usually a small group — 2-3 HR investigators and a compliance manager — reviewing alerts about internal misconduct or data leaks. Regular HR staff who don't use these tools can remain on E3. Recommendation: Select HR/compliance staff receive E5 Compliance for insider risk monitoring.

🏭 Frontline Workers and General Staff

Frontline employees and most general knowledge workers remain on E3 or F-series plans for cost efficiency. Lower risk profile, many of them — E5 at scale is prohibitive. Secure with baseline: MFA via Security Defaults or AAD P1, Exchange Online Protection, basic DLP. If a subset handles sensitive information (regional managers with financial data), selectively upgrade those individuals. Recommendation: Reserve E5 add-ons for roles that truly justify advanced features. Mix F3, E3, and E5 licences in your tenant.

💻 Developers, Finance & High-Impact Individuals

Developers with access to source code and IP could be targets for IP theft — consider Azure AD P2 and Defender for Cloud Apps. Finance users dealing with earnings data or customer financials need stronger email protection (to prevent wire fraud phishing) and may require E5 for Endpoint DLP. Perform a risk assessment by role — identify departments handling crown jewel data or facing elevated threat levels. Recommendation: Selectively assign E5 Security or EMS E5 based on risk assessment; consider E5 Compliance for auto-labelling financial documents.

Licence management tip: Use Azure AD group-based licensing to automate deployment. Create security groups for each role (e.g. "Execs – E5 Security", "Legal – E5 Compliance") and assign licences to those groups. This automates licence deployment as people join/leave roles, and provides clear mapping of licences to business justifications — useful for audits and renewals.

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Evaluating Cost-Effectiveness: E5 Add-ons vs Baseline vs Third-Party

📊 Understand Baseline Capabilities

M365 E3 provides a solid foundation: Azure AD P1 (MFA, conditional access), some threat protection (Defender for Office 365 Plan 1), Intune for device management, core DLP and eDiscovery. If your risk profile is low, you may not need to upgrade everyone. Evaluate recent incidents and gaps: are phishing emails slipping through? Is data exfiltrating undetected? Those gaps indicate baseline is insufficient.

🔍 Identify Gaps and Overlaps

Map E5 features against your specific gaps. If you already have third-party tools, compare: maybe you have a separate CASB, EDR, or DLP product. E5's Defender for Cloud Apps, Defender for Endpoint, or Purview DLP could replace those. Consolidating multiple tools into M365 often saves money and simplifies operations. Microsoft's E5 covers what you might otherwise buy from 4-5 vendors (identity, CASB, EDR, email security, DLP, eDiscovery).

💰 Use Data to Justify ROI

Tangible savings: eliminate subscription costs for third-party products (e.g. dropping a standalone CASB for Defender for Cloud Apps saves tens of thousands annually). A Forrester study found companies using M365 E5 Compliance saw 30-40% reduction in data breach risk and retired several legacy tools, cutting costs by consolidating. Intangible: breach prevention and rapid response — a successful breach costs millions in fines, response, and downtime. Also: automated eDiscovery saves legal teams hundreds of hours of external billing.

🔄 Compare Third-Party Efficacy

A patchwork of solutions means multiple consoles, gaps between tools, and slower response. Microsoft's integrated approach: if Defender for Endpoint detects malware, it can automatically disable the account via Entra ID and flag files for DLP — all under one roof. Independent evaluations (MITRE ATT&CK) show Microsoft's Defender suite among industry leaders. Many CIOs report improved security outcomes after switching to E5 tools along with reduced complexity.

📏 Consider Partial Deployment

Limiting E5 add-ons to 20% of users who account for 80% of risk maximises value. Instead of $X million for all 10,000 employees to E5, spend a fraction licensing 2,000 key users. The "E3 for most, E5 for few" strategy is very common — after a certain point, incremental benefit of E5 for every user doesn't justify the cost, especially for users who rarely access sensitive systems.

🚫 Avoid Redundancy

Paying twice for the same capability is never cost-effective. Once you adopt an E5 add-on, retire redundant third-party subscriptions. Create a roadmap by category (Identity, Endpoint, Email, Cloud App, DLP) — for each, determine if Microsoft now covers it. If yes, plan to eliminate overlap at contract renewal. If not, check Microsoft's roadmap — a gap today might be filled tomorrow.

Best Practices: Consolidating Third-Party Tools into Microsoft

🔗 Adopt an Integrated Security Mindset

Shift from individual point solutions to Microsoft XDR. Use Microsoft 365 Defender and Purview as centralised consoles — alerts from identity, device, and data domains are automatically correlated. A single incident view shows a compromised account leading to malware installation and risky OAuth app usage — all linked. Plan to replace standalone anti-malware, EDR, CASB, and email filtering with corresponding Defender components. Integrate with Microsoft Sentinel (SIEM) to create a single source of truth for incidents.

🪪 Identity and Access Management Consolidation

Consolidate onto Azure AD Premium P2 as your one-stop solution for SSO, MFA, conditional access, and identity governance. Retire separate MFA servers, external SSO gateways, or third-party IAM solutions (Okta, Duo). Azure AD P2 provides Adaptive MFA, passwordless auth, lifecycle workflows, and access reviews. Single identity provider simplifies management, enhances user experience, and improves security (AAD monitors all login attempts globally).

🖥️ Endpoint Security and Device Management

Use Defender for Endpoint + Intune as primary endpoint security and management. Defender for Endpoint P2 provides EDR, vulnerability management, and Azure AD conditional access integration (quarantine compromised devices). Built into Windows 10/11 — reduces agent bloat. Intune unifies policy deployment for Windows, iOS, Android, and Mac. Onboard all endpoints into Defender and manage via Intune/Endpoint Manager for automated cross-network isolation.

🔒 Data Protection and DLP

Use sensitivity labels as the unifying classification system. Apply labels in Office apps, use auto-labelling for rules-based classification, then enforce protection through Purview DLP across Exchange, SharePoint, Teams, and endpoints. Phase out separate DLP products — Purview DLP integrates with Defender for Cloud Apps to extend policies to SaaS apps. All DLP alerts funnel into the Purview portal for uniform response.

📧 Email Security Consolidation

Consider whether Defender for Office 365 Plan 2 can replace your third-party secure email gateway (SEG). Microsoft's Safe Links, Safe Attachments, and AI impersonation detection are on par with many SEG products — and integrated means no complex mail routing. Run Defender in parallel with existing SEG during evaluation, then switch if results are good. Eliminating an external gateway simplifies mail flow and reduces points of failure.

☁️ Cloud App Security (CASB)

If you have a third-party CASB (Netskope, McAfee Skyhigh), evaluate whether Defender for Cloud Apps can fulfil that role. It discovers cloud app usage via firewall logs, controls app permissions, and applies DLP to cloud transactions. Consolidating CASB into Microsoft means cloud threat detections (OAuth abuse, impossible travel, data downloads) feed directly into Azure AD and Defender alerts. Use Conditional Access App Control as a lighter alternative for monitoring remote access.

Continuous improvement: Microsoft releases security and compliance updates frequently. Stay informed via Microsoft 365 Roadmap. Sometimes a feature update lets you decommission another tool. Being agile in adopting new capabilities ensures maximum consolidation value. Also consider Microsoft Defender XDR automation features — automatic investigation and cross-domain remediation reduce analyst workload significantly.

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CIO Recommendations

Align Licence Levels with User Risk

Tiered approach: assign E5 Security to accounts that are prime cyber targets (executives, admins) and E5 Compliance to those handling legal, HR, or sensitive data oversight. Perform a role-based risk assessment. This targeted licensing maximises protection where needed without overspending on low-risk users.

Leverage E5 Add-ons Before Full Suite Upgrades

E5 Security and E5 Compliance add-ons allow incremental adoption of advanced features without requiring everyone to switch to full E5. Start with 500 users in critical roles rather than E5 for all 5,000. You get much of the E5 value at a fraction of the cost. Expand coverage over time only as justified by risk assessment and adoption data.

Compare Bundle vs Standalone Costs

Prefer Microsoft's bundled suites (E5 add-ons, EMS E5) over standalone feature licences. EMS E5 includes AAD P2, Defender for Identity, Cloud App Security, and AIP P2 together — often lower cost than buying two or three separately. Consider standalone (e.g. just Azure AD P2) only for very specific needs or small user sets. For context on Microsoft pricing dynamics, see our EA Renewal Negotiations Playbook.

Consolidate and Retire Redundant Tools

Audit existing security and compliance solutions. Identify overlaps with M365 capabilities. Plan to retire third-party tools covering the same area as E5 features. Common targets: legacy email gateways, separate MDM, on-prem DLP/archive, standalone CASBs, secondary identity providers. Coordinate retirements with Microsoft feature rollouts to avoid gaps.

Maximise Feature Use (Avoid Shelfware)

Buying an add-on doesn't improve security — using the features does. Set project timelines to roll out each component (Defender for Endpoint this quarter, sensitivity labels next quarter). Provide training for IT staff and end-users. Measure feature usage through Microsoft's usage analytics. This strengthens your case at renewal and demonstrates tangible benefits. See our guide on Microsoft Power Platform Licensing for related optimisation strategies.

Pilot and Phase Deployment

Start with pilot groups for Defender for Endpoint or Purview DLP — perhaps IT department devices or a single division. This lets you work out configuration issues, build internal success stories, validate tools function as expected, and fine-tune policies (adjust DLP rules to minimise false positives). Quick wins (MFA for all, basic Safe Links) can be done early with little friction. Complex features (Insider Risk) are phased in later with stakeholder buy-in.

Track Outcomes and Value

Track key metrics: reduction in malware incidents after Defender rollout, phishing emails caught that previously reached inboxes, time saved in eDiscovery, compliance audit findings before and after Purview. Quantify cost savings from eliminating third-party products. Compile metrics into executive reports proving ROI and highlighting security maturity progress.

Maintain Flexibility in Licensing

Microsoft licensing evolves constantly. Stay informed about new add-ons or changes in what's included. Use annual true-up/true-down cycles or monthly per-user licensing to adjust counts. If you have temporary projects requiring more E5 licences (large legal case needing many mailbox holds), use short-term add-on subscriptions rather than over-licensing permanently. Periodically audit who has E5 add-ons and confirm they still need them.

Partner with Stakeholders

Security and compliance involve executive risk committees, legal, HR, and the board. Explain the "native Microsoft" strategy and its benefits. Garner CFO support through cost avoidance (consolidation savings) and CEO support through reduced risk. Work with HR and legal early when deploying Insider Risk or Communication Compliance to address privacy concerns. Consider engaging an independent Microsoft licensing advisor to validate your approach and ensure best-value deals.

Embrace the Full Ecosystem (Long-Term)

Plan for a future where most security and compliance needs are met within Microsoft 365. Microsoft continues enhancing E5: Microsoft Sentinel (cloud SIEM), Microsoft Priva (privacy risk management), AI security copilot. By architecting with Microsoft as the hub, you're cloud-first and ready to adopt future technologies. As a large E5 customer, you gain more support and influence on feature requests. Commit to the platform with periodic re-evaluation.

Microsoft's E5 security and compliance capabilities are powerful tools — when aligned with organisational needs and paired with good policy and training, they significantly reduce risk and complexity. The key: be deliberate and strategic — invest where it counts with role-based risk assessment, avoid one-size-fits-all approaches, consolidate redundant third-party tools, and continually optimise for results. An "E3 for most, E5 for few" strategy delivers maximum security per dollar spent while future-proofing your environment within Microsoft's rapidly evolving ecosystem.

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Fredrik Filipsson

Co-Founder, Redress Compliance

Fredrik Filipsson brings over 20 years of experience in enterprise software licensing, including senior roles at IBM, SAP, and Oracle. For the past 11 years, he has advised Fortune 500 companies and large enterprises on complex licensing challenges, contract negotiations, and vendor management — consistently delivering outcomes that save clients millions across Oracle, Microsoft, SAP, IBM, Salesforce, and Broadcom engagements.

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Maximising Security & Compliance with Microsoft 365 E5 Add-ons