A Brief Guide To Microsoft Office 365 Enterprise

Microsoft 365 Enterprise: A Brief Guide

Microsoft 365 Enterprise combines productivity apps, enterprise email, cloud storage, security, and compliance in one subscription. This guide covers the E1, E3, and E5 plan differences, core apps, security features, compliance capabilities, and deployment best practices — with pricing so procurement can size budgets before the first call.

Key facts

• Microsoft 365 E1: $8/user/month — web Office apps, Teams, SharePoint, OneDrive (1 TB), basic security.
• Microsoft 365 E3: $36/user/month — everything in E1 plus desktop Office apps, 100 GB mailbox, advanced compliance, Intune.
• Microsoft 365 E5: $57/user/month — everything in E3 plus full Defender stack, advanced compliance, Power BI Pro, audio conferencing.
• E3 is the most popular enterprise plan. E5 is required for organizations with advanced security or compliance needs.
• Exchange Online mailboxes: 50 GB on E1, 100 GB on E3/E5, with unlimited archiving on E3/E5.
• EPC Group deploys and governs Microsoft 365 for Fortune 500, federal, and regulated-industry clients.

Understanding Microsoft 365 Enterprise plans

Three tiers cover most enterprise scenarios. The right plan depends on your security requirements, compliance obligations, and whether users need desktop Office apps.

Microsoft 365 E1 — $8/user/month

Web and mobile Office apps, Exchange Online (50 GB mailbox), SharePoint Online, Teams, OneDrive (1 TB), and basic security features. Best for frontline and information workers who primarily need communication and collaboration.

Microsoft 365 E3 — $36/user/month

Everything in E1 plus desktop Office apps, 100 GB mailbox, unlimited archiving, advanced compliance (eDiscovery, DLP, sensitivity labels), Windows 11 Enterprise, and Intune device management. The most popular enterprise choice.

Microsoft 365 E5 — $57/user/month

Everything in E3 plus Microsoft Defender for Office 365 Plan 2, Defender for Endpoint, Defender for Identity, Cloud App Security, advanced compliance (insider risk management, communication compliance), Power BI Pro, and audio conferencing. Required for organizations with advanced security and compliance needs.

Core productivity applications

Every Microsoft 365 Enterprise plan includes these platform services:

• Exchange Online — Enterprise email with 50–100 GB mailboxes, shared mailboxes, resource booking, public folders, and journaling.
• SharePoint Online — Document management, intranet portals, and team sites with co-authoring and enterprise search across millions of documents.
• Microsoft Teams — Unified communication combining chat, video meetings (up to 10,000 attendees for webinars), channels, and app integration.
• OneDrive for Business — 1 TB per user of personal cloud storage with Known Folder Move for Desktop, Documents, and Pictures backup.
• Office desktop apps — Word, Excel, PowerPoint, Outlook, Access, and Publisher with automatic updates on E3/E5.

Enterprise security features

Security capabilities scale by plan. E3 covers most enterprise baseline needs. E5 adds advanced threat intelligence and insider risk management.

• Microsoft Defender for Office 365 Plan 1 (E3) — Safe Attachments, Safe Links, anti-phishing policies.
• Microsoft Defender for Office 365 Plan 2 (E5) — Automated investigation and response, threat analytics, attack simulation training.
• Microsoft Defender for Endpoint (E5) — Endpoint detection and response, vulnerability management.
• Conditional Access — Block access based on device compliance, location, and risk signals.
• Multi-factor authentication — App-based or hardware token MFA for all users.
• Microsoft Sentinel integration (E5) — Cloud-native SIEM fed by Microsoft 365 audit logs.

Compliance and governance capabilities

Microsoft 365 compliance tools are managed from the Microsoft Purview portal. Coverage scales from basic DLP on E1 to full insider risk management on E5.

• Data Loss Prevention — Block sharing of SSNs, credit cards, and PHI by email, Teams, and SharePoint.
• Sensitivity labels — Classify and encrypt documents and emails based on content.
• eDiscovery — Search and export email and file content for litigation or investigations.
• Retention policies — Auto-archive or delete content based on HIPAA, SOX, or GDPR rules.
• Communication compliance (E5) — Monitor and review communications for regulatory and policy violations.
• Insider Risk Management (E5) — Detect and investigate potentially risky user activities.

Deployment best practices

A phased deployment reduces disruption and drives faster adoption.

• Phase 1 — Foundation: Configure Azure AD, MFA, Conditional Access, and Exchange Online. 2–4 weeks.
• Phase 2 — Collaboration: Deploy Teams, SharePoint, and OneDrive with governance policies. 3–6 weeks.
• Phase 3 — Security hardening: Enable DLP, sensitivity labels, Defender for Office 365. 2–4 weeks.
• Phase 4 — Advanced compliance: Configure eDiscovery, retention, insider risk (E5). 2–4 weeks.
• Phase 5 — Training and adoption: Structured user training and change management. Ongoing.

Frequently asked questions

What is the difference between Microsoft 365 E3 and E5?

E3 ($36/user/month) covers desktop Office apps, 100 GB mailboxes, advanced compliance, and Intune. E5 ($57/user/month) adds the full Defender security stack (Endpoint, Identity, Cloud App Security), Power BI Pro, advanced compliance (insider risk, communication compliance), and audio conferencing.

Does Microsoft 365 include compliance tools for HIPAA?

Yes. Microsoft signs a Business Associate Agreement (BAA) covering Microsoft 365. E3 includes DLP policies, sensitivity labels, eDiscovery, and retention policies for HIPAA compliance. E5 adds insider risk management and 6-year audit log retention. You must configure these controls — they are not on by default.

Can I use Microsoft 365 without buying desktop Office apps?

Yes. E1 includes only web and mobile Office apps (Word, Excel, PowerPoint in a browser or on mobile). Desktop Office apps are included in E3 and E5. Frontline workers who only need email and Teams can use E1 at $8/user/month.

How does Microsoft 365 licensing for education differ from enterprise?

Microsoft offers Microsoft 365 A1, A3, and A5 plans for education at significantly lower prices than enterprise plans. A1 is free for qualifying institutions. Academic plans include the same core apps but with FERPA-specific compliance configurations.

How long does a Microsoft 365 deployment take?

A basic Exchange Online and Teams deployment takes 4–8 weeks. A full deployment including SharePoint governance, DLP, Defender, and Intune takes 12–20 weeks for most enterprises. Regulated industries add 4–8 weeks for compliance configuration.

Get expert guidance on Microsoft 365 Enterprise

Talk to a senior Microsoft 365 architect about your licensing and deployment needs. Call (888) 381-9725 or request a 30-minute discovery call.