How to Migrate from Exchange to Office 365

Your organization may need to migrate mailboxes, public folders, emails, contacts, and other items from Exchange Server to Office 365. To perform this job, you can opt for different types of methods available to migrate from Exchange. These may include cutover, staged, or hybrid migration among other methods. 

These methods serve your intended objective depending on your specific migration requirements. Before you start moving your emails to Office, you should be aware of the ideal practices to migrate from Exchange to Office 365.

What are the advantages of Exchange to Office 365 migration?

As an instant benefit, migration to Office 365 optimizes your organization’s messaging infrastructure. It also reduces on-premises maintenance, which boosts scalability. Here are more reasons for migration:

• Collaboration and accessibility: Cloud-based email management through integrated, scalable, and reliable apps.
   
• Work from anywhere: Allows users the access to mailboxes and the contained items across multiple web browsers and devices.
  
• Built-in security features: Microsoft Defender for real-time malware detection, GDPR and HIPAA compliant, disaster recovery through geo-redundant cloud data centers.
  
• Reduced infrastructure expenses: Automatic updates and patching, no physical servers, offloads storage limits to Microsoft

What are the different types of methods for Exchange migration to Office 365?

Choose any of the following methods to migrate from Exchange to Office 365 based on your requirements:

Cutover Migration

This method can support up to 2000 mailboxes. But Microsoft recommends migration 150 or fewer mailboxes to avoid extended downtime. Some of its crucial aspects are as follows:

• Best for small organizations
• The entire Migration occurs at once
• Easiest method with the least complexity 
• Simplest method with minimal complexity
• Possible downtime of around 24-48 hours
• Needs MX record modification post migration

Staged Migration

It allows migration of Exchange mailboxes to Office 365 in multiple batches over time until the completion of the process. During this p, you can continue working without any interruption. Compared to cutover migration, it is more complex as you have to manage every batch carefully.

• Suitable for medium-sized organizations
• Can migrate 150-2000 mailboxes 
• Migrate in phases over weeks or months
• Complicated but less disruptive
• Allows on-premises and cloud environments to co-exist during migration without communicating with each other. 
• After the successful migration of the final batch, the on-premises Exchange Server shuts down completely

Hybrid Migration

Hybrid migration allows the on-premises Exchange Server and Office 365 to coexist within an organization.

• Suitable for large organizations 
• Migrates more than 2000 mailboxes 
• Allows migration of mailboxes at your own pace

• Minimum interruption, best user experience
• Supports cross-premises features

Users on both platforms can exchange emails, making it a two-way communication for an indefinite period unless you end it

Prerequisites to migrating mailboxes from Exchange to Office 365

While all three migration methods follow distinct strategies, their basic operational requirements remain the same. Let’s check them out right here:

Domain ownership and identity

• Register and verify the custom email domain of your company with the Microsoft 365 Admin Center
• Arrange for a completely activated Microsoft 365 tenant account with the requisite licenses to receive migrated accounts

Global administrator rights

The admin should abide by the following practices:

• Get the administrator rights in Microsoft 365 
• Get the Organization management permissions to work in the local Active Directory environment
• Create a remote migration endpoint by using Outlook Anywhere (RPC over HTTP) or MAPI over HTTP protocol to establish a bridge for copying data to the cloud

Network connectivity and infrastructure

• Installing third-party SSL certificate on your local servers will help to securely perform the migration methods
• Firewall must keep the inbound and outbound traffic on Port 443 (HTTPS) and Port 25 (SMTP) open to facilitate web services, secure data syncing, and mail traffic routing
  
• Let the external network connections access the on-premises DNS, Outlook Web App (OWA), and Autodiscover services
  
• The mail flow must work both internally and externally
  
  

Steps to migrate Exchange to Office 365

You may use Exchange Admin Center (EAC) or the command-based Exchange Management Shell (EMS) environment to perform mailbox migration. Here we have chosen to perform Cutover Migration. You may select the migration method that suits your organization the best. Before starting, ensure the Exchange Server has Microsoft support and is healthy. 

Migrate Exchange to Office 365 by using EAC using Cutover Migration

• Open EAC with your admin credentials
• Navigate to Migration, and select Add migration batch 
• In the Add Migration batch page, provide a name in the Give migration batch a unique name
• Select Migration to Exchange Online on the Select the mailbox migration path page and click Next.
• In the Select the migration type page, select Cutover Migration, and click Next
• Carefully read the requirements for cutover migration and click Next.
• In the resulting Set a migration endpoint page, choose a migration endpoint from the dropdown
• Next, in the Schedule batch migration page, choose the start and end time for the migration batch. 
• After configuring all the settings, click Save and select Done to create the migration batch
• Start the migration batch by using the Exchange Admin Center
• Route your MX record directly to Office 365, this will ensure delivery to Office 365 mailboxes
• Delete the cutover migration batch after routing all the email to Office 365 mailboxes
• Assign licenses to the migrated Office 365 user accounts to activate them 

Limitations of manual migration to Office 365

Adopting any of the manual migration methods accompanies a wide list of drawbacks that need prompt address. These include:

• Microsoft throttling, leading to increased downtime during migration
• Calendars and mailbox permissions, shared access rights frequently disappear during manual exports
• Manual mapping can cause a high risk of the data landing in the wrong inboxes
• Lack of advanced filters tend the migration of digital junk along with useful mailbox data
• Tracking migration progress, real-time errors, and missing files is not possible
• The admin must have a penetrating technical knowledge of Exchange migration concepts

To address these shortcomings, experts use Exchange migration tools, such as Stellar Migrator for Exchange

Using Exchange migration tools to migrate from Exchange to Office 365 

Third-party Exchange migration tool can help to move mailboxes from Exchange to Office 365 without the hassles of manual methods. Stellar Migrator for Exchange is a feasible option to serve you cause. It provides numerous features, which make it a suitable alternative to manual migration methods.

• Exchange Server to Office 365 (Exchange Online) Migration
• Office 365 Tenant-to-Tenant Migration
• Ideal for Cross-Forest, Same Domain, & Cross-Domain Migration
• Concurrent mailbox and items migration
• Automated mailbox mapping
• Support for cutover, staged & hybrid migration  
• Support for Multi-Language Mailbox migration
• Migrates selected mailbox folder types
• Customizable date-based and priority-based mailbox migration

Using this software is easy, and it is available online at the official webpage of the product. Opting for it will automate your tasks and help with hassle-free migration. 

Conclusion

Migration of mailboxes from Exchange to Office 365 allows you to draw multiple benefits. For example, it facilitates easy collaboration, allows you to work from anywhere, provides built-in security features, and reduces infrastructure costs. To gain from these advantages, you can proceed with cutover, staged, or hybrid migration. 

These methods allow you to migrate mailboxes according to the permitted limit, ranging from 150 to 2000 mailboxes and more. Alongside serving numerous benefits, they accompany several limitations as well, including the possibility of manual errors, Microsoft throttling, a lack of advanced filters, and more. Moreover, you should have a dexterous technical knowledge to perform these tasks. 

An automated Exchange migration tool, such as Stellar Migrator for Exchange, can address these shortcomings. The tool provides multiple beneficial features and supports the manual migration methods as well. You can download and install the software from its official product page online.