Description: You can change the UPN in AD, but it will not update the user name in Office 365 when DirSync runs. The Office 365 username is configured once during the initial sync and will not be updated.
- Connect to Office 365 with PowerShell
- Change the username by entering the following command:
Change UPN in O365PowerShell1Set-MsolUserPrincipalName -UserPrincipalName email@example.com -NewUserPrincipalName firstname.lastname@example.org