Migrate Exchange Mailboxes to Office 365 using Hybrid Migration

Today, many organizations are migrating their Exchange Server Mailboxes to Office 365 platform. You might have seen many Exchange to Office 365 Migration tools that can do this task for you. However, in this blog post we will describe hybrid migration for migrating Exchange mailboxes to Office 365. You can use the Hybrid Migration for Exchange to Exchange as well as Exchange to Office 365 migration.

Why Companies are migrating from Exchange 2010/2013/2016/2019 to Office 365?

The introduction of Microsoft Office 365 in 2011 has resulted in most companies moving their business email and other details from Exchange to the cloud rather than maintaining a local system. If your business wants to manage its email system in the cloud, Office 365 is the best option.

  • With Office 365 Your team can work remotely, that is, from anywhere at any time, on any device.
  • Office 365 has best malware filtering and spam detection tools
  • You can control your company’s overall costs with Office 365.
  • In addition to reducing the cost of IT support and maintenance, you can streamline the workflow.
  • Your team will be more productive with Office 365’s smart communication and collaboration tools.
  • Overall, the security features provided by Office 365 are strong and reliable.
  • Moreover, upgrades and updates are managed by Microsoft, so the server is robust and scalable.

How to Migrate On-Premise Exchange 2010/2013/2016/2019 to Office 365?

Step 1: Pre-Requisites to Perform Exchange to Office 365 Migration

Access to DNS Records: In order to divert mail flow, and client requests to Exchange online, rather than Exchange on premise, you’ll need access to your public domain’s DNS records. To do this, you’ll need access to Office 365 with a ‘global administrator’ account.

Minimum Requirement Exchange 2010: The minimum requirement to perform on premise hybrid migration is that your on premise sever should Exchange Server 2010 or later.  If you have Exchange Server 2007, 2003, 2000 then you will need some third party applications to perform this migration task.

Certificate: A certificate must be installed on your Exchange server that has been issued by a third party certificate vendor. You cannot use self-signed certificate for this purpose.

Modify User Principle Name: The migration task will become much simpler if we change users UPN to match their email address. Here are the steps to do the same:

  • Open Active Directory >> Select User >> Right Click on it and select Properties
  • Navigate to Account Tab >> their you will see your Users Logon name.

Step 2: Preparing Office 365 for Migration from Exchange 2010/2013/2016/2019

Enable MRS Proxy:

  • Open Exchange Admin Center >> Servers >> Virtual Directories >> EWS >> Edit
  • Now in the Next window >> Check the box for Enable MRS Proxy Endpoint and then click on Save button

Download and Install Azure Active Directory Connector

  • Download and Install Active Directory Connector into your machine, this tool will help us in replicating the groups and users etc. to Office 365 environment.
  • Use Express Settings you want to replicate all users and groups from Exchange to Office 365 environment.
  • Enter Office 365 Login Credentials and then click on Next >> Next >> Check the box Exchange Hybrid deployment >> Install
  • Check if it is showing any warning, correct it and then click on Exit button.

In your Office 365 Enable the option for Exchange Hybrid Deployment  

  • Open Exchange Admin Center >> Hybrid >> Configure >> sign in to Office 365 >> Configure >> Install >> Run >> Next
  • Select the on premise exchange server that you want to use and click on Next button.
  • Now click on Sign-in button >> Next >> Choose the option Full Hybrid Configuration >> Next >> Click on Enable button.
  • After that you will have to create a new txt record in DNS >> after doing the same, check the option “I have created a TXT record for each token in DNS”. >> Verify domain ownership and then click on Next button.
  • Click on Next button if you don’t have any edge transport servers.
  • Choose the CAS Server >> Next
  • In the Send Connector Configuration Window, choose the CAS Server that will connect to office 365 and then click on Next button.
  • Choose your publicly signed certificate.
  • Enter FQDN of you Exchange and click on Next button
  • Click on Update button then Close.

Step 3: Add Domain to Office 365 Account

  • Login to Office 365 >> open Exchange Admin Center
  • Click on the option Add a domain
  • Enter your domain address and click on Next button.
  • Now create a TXT record to verify domain ownership.
  • After doing that click on Verify button.
  • Next choose the option “I will manage my own DNS records” and click on Next button.
  • Now Choose Exchange and click on Next button.
  • Next you will need to create DNS Records to point everything to Office 365. Don’t create these DNS records if you want to still use on premise Exchange Server

If you chose to route all mail and auto discover to Office 365, this is fine. However, you should change the SPF record that Microsoft provides to include the public IP address of your on-premises server, otherwise you may experience mail blockage.

Test your Organizations Mail Flow: Check if you were able to send and receive emails from your on premise exchange server as you were receiving before.

So this the Part 1 one of Exchange to Office 365 migration. We will continue the next steps of Exchange to Office 365 migration in the Part 2.


In this article we have explained steps to migrate exchange to office 365 migration. We will publish the part 2 of migration as quickly as possible. So stay tuned and easily migrate exchange to office 365.

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