While migrating mailboxes, you can manually map the mailboxes on the source server to the mailboxes on the target server. An efficient alternative can be to export the mailboxes to a CSV file and use the CSV file to automatically map the mailboxes.

Here are the steps to export the mailboxes to a CSV file.

Export Mailboxes to CSV from Microsoft 365 using Exchange Admin Center

Steps:

  1. Open Exchange admin center (https://admin.cloud.microsoft/exchange#/homepage).
  2. Select app launcher

    Select app launcher
     
  3. Select Admin in this launcher
  4. Select Users and click on Active users.

    Select Users and click on Active users.
     
  5. Click on the ellipsis icon (three dots) and then select export user.

    Click on the ellipsis icon (three dots) and then select export user.
     
  6. Click on continue to Export the mailboxes as a CSV file.

    Click on continue to Export the mailboxes as a CSV file.

Export mailboxes to CSV in Exchange server and Microsoft 365 using Exchange Management Shell

  1. For Exchange On-Premises, directly open the Exchange Management Shell. For Microsoft 365, connect to the Exchange Server remotely using PowerShell.
  2. Enter the following command:

Get-Mailbox -ResultSize Unlimited | Select-Object DisplayName, SamAccountName, PrimarySmtpAddress | Sort-Object PrimarySmtpAddress | Export-CSV c:\output\mailboxlist.csv -NoTypeInformation -Encoding Unicode

Note: Ensure that the c:\output folder exists before running the command. If it does not exist, create it manually or specify a different directory.

Export Mailboxes to CSV in Exchange server using Exchange Admin Center

  1. Login to Exchange Admin Center and navigate to Recipients > Mailboxes.

    Login to Exchange Admin Center and navigate to Recipients > Mailboxes.
     
  2. Click on the ellipsis (…) button and select Export data to CSV file.

    Click on the ellipsis (…) button and select Export data to CSV file.
     
  3. In the Export data window, select the checkboxes for the data you want to include in the export. Click the Export button and the data will be downloaded as a CSV file to your local drive.

    In the Export data window, select the checkboxes for the data you want to include in the export. Click the Export button and the data will be downloaded as a CSV file to your local drive.

Note:

  • The downloaded CSV file can be opened in Excel or any other tool to review the mailbox data.
  • Ensure you have the necessary permissions to perform export actions in the Exchange Admin Center.