A complete technical walkthrough of Microsoft 365 Business Premium,
covering Outlook mailboxes, Entra ID identity management, Teams message retention,
and Microsoft Purview eDiscovery for auditing and data governance.

1 Overview of Microsoft 365 Business Premium

License Components

• Outlook Exchange Online (50 GB mailbox)
• Teams for chat, calls, and meetings
• OneDrive and SharePoint for cloud storage
• Intune for device management
• Entra ID (former Azure AD) for authentication and SSO
• Purview for compliance and eDiscovery
• Defender for Business for security protection

Each user license can activate Office apps on up to 5 PCs/Macs + 5 tablets + 5 phones.
All services update automatically after login with a valid subscription.

2 Outlook and Exchange Online Mailboxes

• A Business Premium tenant automatically provisions an
  @yourtenant.onmicrosoft.com mailbox.
• You can add a custom domain (e.g., @yourcompany.com) in
  Microsoft 365 Admin Center → Settings → Domains.
• DNS records (MX, SPF, DKIM, DMARC) are handled automatically.

Mail data is stored in Exchange Online, enabling retention and eDiscovery.

3 Microsoft Entra ID (former Azure AD)

Purpose

• Central identity provider for the tenant
• User, group, and role management
• SSO for internal and third-party apps
• MFA and conditional access policies

Admin Portal

4 Teams Integration Architecture

Teams Admin Center provides usage reports:
message counts, meetings joined, call duration, and device types.

5 Microsoft Purview Compliance Portal

New unified entry point: https://compliance.microsoft.com

Included modules for Business Premium:

• Audit – activity logs (90 days)
• eDiscovery (Standard) – search and export content
• Data Lifecycle Management – retention policies
• Communication Compliance (basic rules)

6 Default Retention and Policy Extension

Create a Permanent Retention Policy

1. Open Purview → Data Lifecycle Management → Microsoft 365 → Retention Policies
2. Create policy → select Teams chats / channel messages
3. Choose Keep Forever
4. Apply to All Users → Save → Publish

After this, Teams messages remain permanently searchable and recoverable.

7 eDiscovery (Standard) Workflow

Step 1 Open Module

Purview → Solutions → eDiscovery → eDiscovery (Standard)

Step 2 Create a Case

Example name: Teams_Compliance_Audit

Step 3 Add Search

• Locations: Teams Chats and Mailboxes
• Keywords: e.g. ("resignation" OR "quit" OR "leave company")
• Date range: optional
• Run the search

Step 4 View and Export

Results show: sender, recipients, timestamp, and message snippet.
Select Preview to see context or Export to download a ZIP package.

8 Export Structure and HTML Preview

TeamsChatExport_20251112_XXXX/
├─ manifest.csv
├─ TeamsChat_1.html
└─ Metadata/
    ├─ MessageDetails.csv
    └─ Attachments/

Example HTML View

───────────────────────────────
User A  ( 2025-11-10 17:42 )
I haven’t mentioned the resignation yet.

User B  ( 2025-11-10 17:43 )
When will you bring it up?

User A  ( 2025-11-10 17:44 )
Probably end of the month, after handover.
───────────────────────────────

Each file includes message context, timestamps, and participants—
allowing a full reconstruction of conversation flow.

9 Permissions Required for eDiscovery

Add roles via Purview → Permissions → Microsoft Purview solutions.

All features above are included in Business Premium—no extra license needed.
(Only eDiscovery Premium and Advanced Audit require E5 plans.)

10 Teams Privacy and Compliance Reality

Even deleted messages remain discoverable until their retention period expires.

Conclusion for users:

Teams chat is not a private messenger.
All content belongs to the organization and may be retained or audited.

11 License Tier Comparison

12 Logical Architecture Summary

[User]
   ↓
[Teams Client]
   ↓
[Exchange Online / SharePoint / OneDrive]
   ↓
[Microsoft Purview Services]
   ├─ eDiscovery
   ├─ Audit
   ├─ Data Lifecycle Management
   ↓
[Compliance Admin Center]

13 Key Takeaways

1. Business Premium integrates identity (Entra ID), collaboration (Teams), and compliance (Purview).
2. Teams chat data is retained by default for 30 days unless a policy extends it.
3. eDiscovery (Standard) can search and export full conversation context in HTML.
4. Chat content is organizational data, not personal property.
5. Administrators should set clear retention and privacy policies for all users.

Useful Portals

• Microsoft 365 Admin Center
• Teams Admin Center
• Entra Admin Center
• Microsoft Purview Portal