Exchange On-Premises to Office 365 Migration Guide
Complete step-by-step guide to migrate Exchange on-premises mailboxes to Office 365. Learn about connector configuration, authentication options, and migration best practices.
Overview
Cloudiway provides a comprehensive platform for migrating Exchange on-premises mailboxes to Office 365 (Microsoft 365). The migration process involves five key steps: creating source and target connectors, configuring global settings, building your user list, and executing the migration.
What Gets Migrated
- Email messages & attachments
- Calendar events
- Contacts
- Tasks
- Notes
- Folder structure
Step 1: Create Exchange On-Premises Source Connector
Navigate to Connectors → New and select "Exchange On Premises" as the connector type.
Configuration Requirements
Server URL Format
Step 2: Create Office 365 Target Connector
Create a corresponding Office 365 connector to define your migration destination. Navigate to Connectors → New and select "Office 365" as the connector type.
You'll need to configure Azure AD application credentials with the appropriate permissions. See our Azure App Registration Guide for detailed setup instructions.
Required Permissions
- Exchange.ManageAsApp (Application)
- full_access_as_app (Application)
Step 3: Configure Global Settings
Access Mails → Global Settings to define migration parameters and specify what content to migrate.
Content Options
- Mailbox items (emails)
- Calendar events
- Contacts
- Tasks
Filter Options
- Date range filter
- Folder exclusions
- Size limitations
Step 4: Build User Migration List
Navigate to Mails → User List to create or import your migration users.
Create Manually
Add users one by one with source and target email addresses. Best for small migrations.
Mails → User List → Create Import from CSV
Bulk import users from a CSV file. Include source email, target email, and optional metadata.
Mails → User List → Import Step 5: Execute Migration
Select users from your migration list, optionally organize them into batches, and initiate the migration.
Run Audit Task (Recommended)
Assess mailbox sizes and identify potential issues before starting the actual migration.
Select Users
Choose individual users or select entire batches for migration.
Start Migration
Click the migrate button to begin the migration process. Monitor progress in real-time.
Delta Migration
Authentication Options
Impersonation
A single migration account impersonates each user to access their mailbox. Requires ApplicationImpersonation role in Exchange.
Recommended for enterpriseDelegation
The migration account has Full Access permission to each target mailbox. Suitable when impersonation isn't available.
Alternative optionSelf Service
Users provide their own credentials to migrate their mailbox. Ideal for hosted environments where admin access isn't available.
Best for hosted ExchangeScreenshots
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