Exchange Server to Exchange Online Migration: Complete Guide

  

Published By Mohit Jha

Approved By Nimisha Ramesh

Published On August 18th, 2026

Reading Time 9 Minutes Reading

Are you interested in migrating Exchange Server to Exchange Online? You can easily do so using Microsoft native methods, i.e., Cutover, Staged, or Hybrid. This will depend on number of Exchange mailboxes and their versions.

However, it might require manual setup and some scripting, which includes high risk of data loss, a lot of time, and human effort.

In such scenario, FreeViewer Exchange to Exchange Online Migration Tool is an automated software that allows users to move multiple Exchange mailbox data to the cloud without risk of losing data integrity. It can efficiently transfer up to 200 mailboxes directly without downtime and PowerShell scripting.

This guide will compare both manual and professional software for Exchange Server On Premise to Exchange Online migration with a brief explanation according to user needs.

Let’s begin the article by looking at some user queries.

User’s Query 1:

User’s Query 2:

Steps to Migrate Exchange Server to Office 365

Now, it is time to go through step wise instructions for mentioned solution above:

1. Launch and run the migration software on your system.



2. Choose source platform as Exchange Server and destination platform as Office 365.



3. Select or Deselect data items and apply date filter according to your choice.



4. Choose Microsoft Exchange Server version and enter other required information.



5. Now, users have to type their Office 365 Admin Email Address and Application ID.



6. One has to mention source users. For that, you can either fetch users or Import users through CSV file.



Note: The CSV file template can be downloaded from tool itself.

7. Now, Map Source mailboxes with destination mailboxes and hit Validate option.



8. Finally, press Start Migration button to begin Exchange Server On Premise to Exchange Online migration process.

After understanding its working, we assume that you do not have to opt for any other solution. Still, if you want to know other approaches, then it is right time to know some manual native Microsoft methods.

Let’s quickly understand them in detail.

Manual Method 1: Cutover Migration

This type of migration method allows you to export less than 2,000 mailboxes in a single shot. The cutover migration supports Exchange versions 2003, 2007, 2010, & 2013. This method can be divided into four stages.

Follow them one after another to finish Exchange Server to Office 365 migration process without facing any hurdles.

Step 1: Planning

The process of Exchange Server to Office 365 migration needs proper planning including steps mentioned below:

1. First, open the site of the Exchange Deployment Assistant
2. As soon as the site is launched, you will have 3 options. For a cutover migration, you need to choose the Cloud Only option. Therefore, click on Cloud Only
3. Now, you need to answer all the questions that are asked of you
4. Once it is done, click on the Next arrow
5. This Exchange Deployment Assistant will create a step-by-step guide for you that you need to follow.

Step 2: Testing Existing Setup

Now, with help of guide provided by Exchange Deployment Assistant, you need to be sure that Exchange Server infrastructure supports Outlook Anywhere & Autodiscover. Once this step is completed, you can go to the next stage of this process to migrate Exchange Server to Office 365:

1. Firstly, open Microsoft Remote Connectivity Analyzer site.
2. Choose MS Outlook Anywhere (RPC over HTTP) test and click Next.
3. Enter requested information. You need to confirm that you are using Autodiscover for detection of server settings.
4. Now, type in Verification code and click Perform Test.

In case the test fails, use the report generated and Exchange Deployment Assistant for the resolution of issues.

Step 3: Migrate Exchange Server to Office 365 by Configuring Cutover Migration

1. First, open Internet Explorer and then log in to Admin Center of Office 365.
2. Now, open Exchange Admin Center and click on Migration.
3. Then, click on drop-down menu & choose Migrate to Exchange Online.
4. You need to choose Cutover migration followed by clicking on Next.
5. Now, enter the credentials of on prem account and click Next. At time of proper configuration, Autodiscover should resolve on premise Exchange Server and RPC Proxy Server.
6. Then, click on Next and enter name for New Migration Batch. Click Next button once again.
7. In this step, you need to choose a user who will get report after migration. Users can select multiple accounts. Now, if you are prepared to migrate Exchange Server to Office 365, then start batch automatically. If not, then select manually start batch later.
8. Click New and new migration batch will be created.
9. User have to wait for some time for completion of process. To see details of migration, click on View Details option.

Step 4: Completion of Migration

Once synchronization from Exchange Server to Exchange Online is completed and all accounts are provisioned, report will be emailed to you. Now, as soon as you get report, you can proceed to complete process.

1. Migrate Public Folders: This means migration of Exchange Public folders to Exchange Online.
2. Assign Office 365 licenses to all users.
3. After completion of migration of all emails to Office 365 and replication of MX record DNS, you can stop process of migration.

Manual Method 2: Staged Migration

In staged transition, users move mailboxes in small batches rather than migrating on premise server data at once. This technique is useful when organizations need to transfer users while keeping some of mailboxes in cloud for some time.

Steps to Migrate Exchange Server to Exchange Online:

1. Start process by assessing and prioritizing which mailboxes are required for staged transition.
2. Validate destination domain ownership within Office 365 system.
3. Now, configure directory synchronization to establish user accounts.
4. Make list of all user mailboxes that need to be transferred to cloud.
5. Connect on premise server and Office 365 environment for staged migration.
6. Run Exchange on premise to Exchange Online batch migration.
7. Now, repeat same for other batches to reduce user disruption.
8. Export tranferred on premise mailboxes to IMAP enabled users.
9. Verify email flow to M365 to maintain communication without any hassle.
10. Check each staged migration batch before finalizing.

Manual Method 3: Hybrid Migration

This method is best when migrating up to 200+ mailboxes to Exchange 2013 to Office 365. Here, users can easily connects on premise server with Exchange Online and then transfer their mailboxes while maintaining data integrity.

It is ideal for large organisations that require controlled migration instead of instant transition. Follow steps mentioned below:

1. Configure hybrid migration wizard between Exchange Server and Exchange Online to begin moving legacy data to new system.
2. Get secure proxy service that enables transfer of data between your legacy and new email environment.
3. Use Exchange Admin Center to start moving mailboxes in bulk. Follow Hybrid Migration wizard to help you smoothly move your emails from one system to another.
4. Once you migrate Exchange server to Office 365, delete all unwanted on premise data, which allows you to manage it properly.

Exchange Server to Exchange Online: Manual vs Automated Method

Conclusion

This guide helps users who are migrating from Exchange Server to Exchange Online. As it becomes critical challenge for large organisations, which require proper planning and deployment to not to lose imporytant mailbox data.

However, we have mentioned all ways to move multiple on premise to Office 365, such as FreeViewer Exchange Server to Office 365 Migration tool which enables all users to transfer up to 200+ mailboxes without losing data hierarchy and within timeframe. Users can download this suggested software for reliable and accurate migration results.