How to Migrate Emails to Office 365

This tutorial shows you how to migrate your mailboxes to Office 365 from a variety of sources, whether it's Exchange On-Premises, Lotus Notes, IMAP or Zimbra servers, or even Gmail as part of a broader cloud transition.

Universal Migration Process

The migration process remains the same regardless of your source. Whether you're migrating from Exchange, Lotus Notes, IMAP, Zimbra, or Gmail, Cloudiway provides a unified approach.

To illustrate this migration process, we've prepared a comprehensive video that shows how to migrate your emails between Office 365 tenants. The same principles apply to any source platform.

5M+

Mailboxes Migrated

99.9%

Success Rate

24x5

Expert Support

20+

Source Platforms

Supported Source Platforms

Cloudiway supports migration from virtually any email platform to Office 365:

Exchange On-Premises

Exchange 2010, 2013, 2016, 2019
Full mailbox migration
Public folders support

Lotus Notes / Domino

IBM Notes NSF migration
Archives and calendars
Domino directories

IMAP Servers

Zimbra, Postfix, Dovecot
Any IMAP-compatible server
GroupWise, Kerio, MDaemon

Gmail / Google Workspace

Gmail to Office 365
Labels converted to folders
Contacts and calendars

Migration Process

The migration process consists of four main steps:

Create a Project

Set up a new migration project in the Cloudiway platform. Define your source and target environments.

Configure Connectors

Create source and target connectors to connect to your email systems. Authorize Cloudiway via admin consent.

Define Users

Define your list of users to migrate. Import from CSV or use automatic discovery from your source system.

Launch Migration

Start the migration process. Monitor progress in real-time and use delta sync for incremental updates.

Pro Tip:

Use Cloudiway's automatic user discovery to quickly populate your migration list. Simply connect to your source system and let Cloudiway identify all mailboxes.

Migration Strategies

Choose the migration strategy that best fits your organization's needs:

Big Bang

Migrate all users simultaneously
Best for small organizations
Weekend cutover possible

Staged

Migrate in batches over time
Gradual transition
Minimal disruption

Cutover

Full migration with coexistence
Users switch when ready
Mail routing maintained

Cloudiway supports all migration strategies thanks to its delta pass mechanism. This allows you to perform incremental synchronization, ensuring no data is lost regardless of which strategy you choose.

Key Considerations

Before starting your migration, consider these important factors:

Domain Migration

Plan your domain migration strategy. Decide which domains move to Office 365 and configure DNS records.

Mail Routing

Configure mail routing during coexistence. Ensure emails reach users regardless of migration status.

Microsoft Throttling

Microsoft applies throttling limits. Cloudiway optimizes API calls to maximize throughput within limits.

Bandwidth Planning

Large migrations require bandwidth planning. Consider scheduling during off-hours for optimal performance.

Data Filtering:

Cloudiway allows you to filter emails by date, enabling you to exclude old emails and reduce migration time. This is particularly useful for large mailboxes with years of accumulated data.

Why Not Microsoft's Free Tools?

While Microsoft offers free migration tools, they come with significant limitations that can impact your migration project:

Microsoft Limitations

No permission migration
No distribution lists
No resource mailboxes

Cloudiway Advantages

Full permission migration
Distribution list support
Rooms & equipment

The Cloudiway Solution

Cloudiway provides a complete migration platform designed for Office 365 migrations:

Zero Downtime Migration

Users continue working in their source system while data syncs in the background. Final cutover takes minutes.

Delta Synchronization

Incremental sync captures all changes during migration, ensuring complete data integrity.

20+ Source Platforms

Migrate from Exchange, Lotus Notes, IMAP, Zimbra, Gmail, and virtually any email system.

Expert Support

Dedicated migration specialists guide you through planning and execution.

Ready to Migrate to Office 365?

Get a free migration assessment. We'll analyze your source system and provide a detailed migration plan.

Start Free Trial Get Expert Help

Frequently Asked Questions

What email sources can I migrate to Office 365?

You can migrate emails from virtually any source: Exchange On-Premises (2010, 2013, 2016, 2019), Lotus Notes/Domino, IMAP servers (Zimbra, Postfix, Dovecot), Gmail/Google Workspace, and other email platforms.

What is the migration process to Office 365?

The migration process involves four main steps: 1) Create a project in Cloudiway, 2) Configure source and target connectors, 3) Define the list of users to migrate, and 4) Launch the migration.

What migration strategies are available?

Three main strategies: Big Bang (migrate all users at once), Staged (migrate in batches over time), and Cutover (migrate with coexistence period). Cloudiway supports all strategies with delta pass mechanisms.

What are the key considerations for email migration?

Key considerations include: domain migration planning, mail routing configuration, Microsoft throttling limits, bandwidth optimization, and data filtering options to exclude old emails.

Why not use Microsoft's free migration tools?

Microsoft's free alternatives have limitations: they don't migrate permissions, distribution lists, resource mailboxes (rooms/equipment), or provide comprehensive reporting and delta synchronization.

How long does email migration to Office 365 take?

Migration duration depends on data volume and source platform. Cloudiway processes approximately 10-15 GB per hour per migration slot. A typical 50-mailbox migration takes 2-5 days with parallel processing.