Office 365 E3 Microsofts Cloud Based Suite

Microsoft 365 E3 (formerly Office 365 E3) is the enterprise-grade productivity and security suite that serves as the backbone for organizations with hundreds to hundreds of thousands of users. At $36/user/month, E3 delivers the full Microsoft Office desktop suite, Exchange Online with unlimited archiving, SharePoint Online, Microsoft Teams, and a comprehensive set of security and compliance tools that meet the baseline requirements for HIPAA, SOC 2, and GDPR compliance. For most enterprise organizations, E3 represents the optimal balance between capability, cost, and compliance coverage.

What Is Included in Microsoft 365 E3

Microsoft 365 E3 bundles productivity applications, cloud services, security features, and Windows Enterprise into a single per-user license:

• Office desktop applications – Word, Excel, PowerPoint, Outlook, Access (PC), Publisher (PC), and OneNote installed on up to 5 PCs/Macs + 5 tablets + 5 phones per user with always-current feature updates
• Exchange Online Plan 2 – 100 GB mailbox per user, unlimited in-place archiving, hosted voicemail, shared mailboxes, resource mailboxes, and distribution groups
• SharePoint Online Plan 2 – 1 TB base storage + 10 GB per user, team sites, communication sites, hub sites, and advanced customization capabilities
• Microsoft Teams – Chat, video conferencing (up to 1,000 participants), channel-based collaboration, app integrations, and webinar hosting (up to 1,000 attendees)
• OneDrive for Business Plan 2 – 5 TB per user for personal file storage with sync, sharing, known folder move, and ransomware detection and recovery
• Windows 11 Enterprise E3 – Windows Enterprise upgrade rights with Autopilot deployment, Windows Update for Business, and AppLocker application control
• Microsoft Intune Plan 1 – Mobile device management (MDM), mobile application management (MAM), and PC management for endpoint security

Security Features in Microsoft 365 E3

E3 includes a robust security foundation that addresses the majority of enterprise security requirements:

• Azure Active Directory Premium P1 – Conditional Access policies, self-service password reset, group-based licensing, dynamic groups, and application proxy for on-premises app access
• Microsoft Defender for Office 365 (basic) – Exchange Online Protection (EOP) with anti-malware, anti-spam, and connection filtering. Note: advanced Safe Attachments and Safe Links require E5 or Defender Plan 1 add-on
• Multi-factor authentication (MFA) – Azure AD MFA with conditional access integration, hardware token support, and number matching
• Intune endpoint management – Device compliance policies, app protection policies, Windows Autopilot for zero-touch deployment, and remote wipe capabilities
• BitLocker and device encryption – Managed disk encryption for Windows devices with centralized recovery key storage in Azure AD
• Microsoft Entra ID Protection (basic) – Risk-based conditional access evaluating sign-in risk and user risk signals

Compliance and Information Governance

E3's compliance features cover the baseline requirements for regulated industries, though E5 extends these with advanced capabilities:

• Data Loss Prevention (DLP) – Policies that detect and protect sensitive information (SSN, credit card numbers, PHI) across Exchange, SharePoint, OneDrive, and Teams with configurable actions (block, notify, encrypt)
• Retention policies – Automated retention and deletion of content across all Microsoft 365 workloads based on content age, labels, or regulatory requirements
• eDiscovery (Standard) – Content search across all workloads, legal hold, case management, and export for legal and regulatory investigations
• Sensitivity labels – Manual and recommended labels that apply encryption, visual markings, and access controls to documents and emails
• Audit logging (Standard) – 180-day audit log retention for user and admin activities across all Microsoft 365 services (E5 extends to 1 year with Advanced Audit)
• Information barriers – Policies that prevent specific groups from communicating or sharing content (useful for financial services Chinese wall requirements)

Microsoft 365 E3 vs. E5: When Do You Need E5?

E5 adds approximately $21/user/month in additional capabilities. Here is when the upgrade is justified:

• Upgrade for advanced threat protection – E5 includes Microsoft Defender for Endpoint (EDR), Defender for Office 365 Plan 2 (Safe Attachments, Safe Links, automated investigation), and Defender for Cloud Apps (CASB)
• Upgrade for advanced compliance – E5 adds Advanced eDiscovery (predictive coding, review sets), Insider Risk Management, Communication Compliance, and Customer Lockbox
• Upgrade for Power BI – E5 includes Power BI Pro for every user, which saves significant licensing costs if more than 50% of your organization needs BI capabilities
• Upgrade for Phone System – E5 includes Microsoft Teams Phone System for replacing traditional PBX; with E3, this requires a separate $8/user/month add-on
• Stay on E3 when your organization has fewer than 500 users, does not handle highly sensitive data, and does not need advanced analytics or phone system integration

Deployment Best Practices for Enterprise E3 Rollouts

Large-scale E3 deployments require careful planning to ensure successful adoption and security:

• Phased rollout – Deploy to IT staff first (pilot), then early adopters (100–200 users), then department-by-department. This identifies issues before full-scale deployment
• Azure AD Connect configuration – For hybrid environments, configure Azure AD Connect for identity synchronization, password hash sync or pass-through authentication, and seamless SSO
• Conditional Access baseline – Implement a minimum set of Conditional Access policies at deployment: require MFA for all users, block legacy authentication, require compliant devices for sensitive applications
• DLP policy activation – Deploy DLP policies in audit mode first, review false positive rates for 2–4 weeks, then switch to enforcement mode
• Change management – Invest in user training, champion programs, and communication plans; the technology is only as effective as user adoption allows

Why Choose EPC Group for Microsoft 365 E3 Deployment

EPC Group has 29 years of enterprise Microsoft consulting experience and Microsoft Solutions Partner status (former Microsoft Gold Partner 2003–2022). We have deployed Microsoft 365 E3 for organizations ranging from 500 to 50,000+ users across healthcare (HIPAA), financial services (SOC 2), and government (FedRAMP). Our team has authored 4 bestselling Microsoft Press books on Microsoft technologies, and we bring deep expertise in security configuration, compliance framework implementation, and change management that ensures your E3 investment delivers maximum value from day one.

Frequently Asked Questions