Set-Mailbox username -WindowsEmailAddress username@domain.com

Set-ExecutionPolicy RemoteSigned$LiveCred = Get-Credential$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://ps.outlook.com/powershell/ -Credential $LiveCred -Authentication Basic -AllowRedirectionImport-PSSession $Sessionget-mailbox | get-mailboxstatistics | select DisplayName,ItemCount,TotalItemSize | export-csv “MailboxSizes.csv”