NOTE:

• To perform Outlook PST to Office 365 migration, the Office 365 account that you are Impersonating must be an Office 365 Exchange Mailbox user account.

• There is no need to set Impersonation rights to all the Office 365 Exchange mailbox accounts. Set Impersonation rights to only the Administrator
  user and use this Administrator user for Office 365 login via the EdbMails application during Outlook PST to Office 365 migration. Using this Impersonated user,
  EdbMails will list all the other users and you can map them to any Mailboxes for Outlook PST To Office 365 migration.

Steps to perform Outlook PST to Office 365 Migration

1. Open www.office.com
   Enter the credentials of your Office 365 Administrator Exchange Mailbox account to Sign in.

2. Click on the button from the top left corner to open the menu as shown below
   

3. Click on security & Compliance button as shown below
   

4. Click on permissions
   

5. Click on "Go to Exchange Admin center".
   

6. Double click on the role group "Discovery Management".
   

7. • a. Click '+' to Add Roles
     Select 'ApplicationImpersonation' and click on add then click on OK.
     

   • b. Click '+' to add the members.
     Select the members who are having the administrator rights and click on add then click on OK.
     

8. Click on Save to complete the Impersonation.

9. Now Open the EdbMails application, Login and select the PST file that you wish to export to Office 365.

10. On the main GUI, select the Mailboxes that you wish to export and Click the button "Export Selected Mailboxes / Folders..."

11. Select the Export Method as "Export Selected Mailboxes / Folders to Office 365" and Click "Continue", as shown below
    

12. Login with Office 365 Impersonated administrator credentials for Office 365 Service authentication.
    

13. After successful login, you will be listed with all the associated office 365 users. Where in you can map it respective mailboxes.
    

14. After mapping the Mailboxes, click the "Export PST to Office 365" button to continue with the PST to Office 365 migration.

15. During export operation, the progress will be displayed as shown in the below screenshot.
    

16. Once the Export operation is completed, the message "Export operation has been completed." will be prompted.

NOTE: Please note that according to Microsoft, Office 365 Small Business plans cannot assign impersonation rights manually. The default built-in admin account is the only one who can hold such a permission.