It's not an unfamiliar scenario with all of the rebranding that's happening these days. Your Office365 group has the wrong mail domain and now you want to change it. It's the kind of thing that you'd expect to be able to change via the admin portal. After all, there's a neat little domain selector box on the page. Alas, that's not how Office 365 groups work. You need PowerShell for that one. PowerShell to the Rescue PowerShell, the interface you have when you don't have an interface... Here's how to change the domain on your group. Run PowerShell as an Administrator and type the following commands; Set-ExecutionPolicy RemoteSigned $UserCredential = Get-Credential $Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $UserCredential -Authentication Basic -AllowRedirection Set-UnifiedGroup -Identity " Group English Name " -PrimarySmtpAddre...