Hosted Exchange Server to Office 365 Migration – Everything You Need to Know

Mark Regan ~ November 6th, 2021 ~ Microsoft Office 365

In this blog post, we are going to discuss hosted exchange server to office 365 migration in detail. Read the complete blog and stay tuned with us for more information.
Mr. Clarice work in an organization where he uses to manages the various projects of their clients. He had shared with us the story of his recently completed project on Hosted Exchange Server to Office 365 Migration.

Mr. Clarice told us that a few days back I got a new migration project on Hosted Exchange Server to Office 365 mailbox. It was something new and challenging for me to perform the migration as it is not an easy task to migrate multiple files from Hosted Exchange Server to Office 365 mailbox.

Now, the challenge was somehow higher for me to import Hosted Exchange Server data to the O365 mailbox. I have outlined a solution along with some obstacles, which I faced in this hosted server to cloud migration.

Similar Blog Post – Migrate Exchange Server to Office 365

Preparation before migration of Hosted exchange server to Office 365 migration

Prepare the source hosted exchange environment

Users has to follow the detailed steps mentioned below:

  1. First, create a new account for the migration and then grant full access rights to each mailbox for the respective account. Now, run the PowerShell cmdlet.
Get-Mailbox -ResultSize unlimited | Add-MailboxPermission -AccessRights FullAccess -User <the user account name>
  1. After that, the user has to allow the impersonation right to the user. It is very important to have impersonation rights for a large size migration. Run the cmdlet.
New-ManagementRoleAssignement -Role ApplicationImpersonation -User <username>
  1. Export the mailboxes to a CSV file.
    NOTE: If you are an administrator, then you do not need to provide the password for every mailbox. But a non-administrator needs to provide both mailboxes and passwords in the CSV.

Prepare the destination environment (Office 365)

Follow these steps for having a hassle-free pre-migration procedure:

  1. First, set up the user account to receive the mailboxes.
  2. Now, create a new admin account that will have all the permission related to the mailbox.
    NOTE: You need to create a new admin account because if the user is a part of the Domain Administrator, Schema Administrator, or Enterprise Administrator groups, then they cannot have any administrative rights for migration. There is a default security setting in Exchange Server which prevents such admin accounts from migration even if they have the required permission.
  3. Thereafter, create a new Exchange PowerShell session for the migration.
$s = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri -Credential $cred -Authentication Basic -AllowRedirection
  1. Grant the permission for migration with the following cmdlet:
Get-Mailbox -ResultSize Unlimited | Add-MailboxPermission -AccessRights FullAccess -Automapping $false -User <username>
  1. Disable the throttling for the Administrator account.
  2. After that, verify Administrator account is accessible in EWS.
  3. During migration, if the attachment along with the messages is larger than 10 MB, then you need to change some limit settings in the destination mailboxes – increase maximum message size limit, maximum accepted content length, maximum receive message size, and maximum accepted request length.

Heavy User-Profile

When I encountered the actual users and start my exploration over their utilization on Hosted Exchange Server. I found it somewhat a step-forward challenging. As this organization is of Job Consultant Company, which conducts various job interviews for several people. The main challenges that I felt were:

Challenge 1:

The first challenge was the size of mailboxes with extravagant limits on Hosted Exchange Server account. They had accrued quite a mass of emails from the last 3 years. After clearing a lot of old stuff still, there was about 50 GB with 48 GB rest that is not big but still the main point for download speeds.

Challenge 2:

Another challenge was that they need to migrate particular emails from some mailbox of Hosted Exchange Server to Office 365 account. So, I had to manage the account that needs specific email migration.

Plan for Migration from Hosted Exchange Server to Office 365

The actual plan that I made. But I feel that it will take a lot of time. Then, one of my teammates recommended me to utilize Email Backup Wizard. As, it’s a direct way to export from Hosted Exchange Server to Office 365. I found it somehow interesting, as the task was high and the time was quite less.

Therefore, we contacted to support and united all my problems with them. Then, they helped us throughout the procedure of migration from Hosted Exchange Server to Office 365. Even, directed me in many other technical things allied to the same.

Software to Export Hosted Exchange Server to MS Office 365

We invested on the application.  As migration from Hosted Exchange Server to Office 365 was large in size. But we utilized their demo of the tool first before buying the Hosted Exchange Server to Office 365 Converter as a way to test the procedure of data migration from hosted server to cloud.

  • Download and run BitRecover Hosted Exchange Server to Office 365 Converter on your system.


  • From list of email source select Hosted Exchange Server option.

Run Software

  • Enter credentials of your Hosted Exchange Server along with Server name to execute the data migration from Hosted Exchange Server to Office 365 account and click on Backup.

Hosted Exchange Server

  • The tool will list all the folders along with the message count.

list all the folders

  • From the list of file saving options, select Office 365.

saving options

  • If you want to save messages at default folder then, just check for an option “save messages in the default folder.”

save messages in the default folder

  • Check “I am Admin” option only if you are an admin. It helps to perform multiple mailbox mapping. For using user mailbox be confirm that the Application Impersonation and mailbox delegation is allowable.

I am Admin


  • If you need to change language then, choose change language option.

language option

  • Enter the credentials of Office 365 account on tool’s panel.

credentials of Office 365

  • If you want to migrate selective data so, check “Use Advance Settings for Selective Backup” option.

Use Advance Settings

  • Enter the date range with other desired details for preferred email backup >> click on the backup button to start the process.

Hosted Exchange Server to Office 365 Migration

  • Once it is done, you will have the message of completion.
Finally! by utilizing this software I easily exported data from Hosted Exchange Server to Office 365 easily. By moving the data, I easily finished my project. I am really Thankful for serving me out in this migration project. Even, in my all other projects of migration, I used this Software.


In the above post, we have briefly discussed hosted exchange server to Office 365 migration. Users will not face any hassle in performing the entire task without any hassle. We know that hosted exchange migration is a complicated task. But not anymore, after reading this post user will not face any issue in the completion of this process.

We hope this blog satisfies all the technical and non – technical users. If the still issue persists then the user can contact our live support team.