Conectarse a Exchange Online
Abrimos una consola PowerShell. Y ejecutamos estos comandos:
$UserCredential = Get-Credential
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $UserCredential -Authentication Basic -AllowRedirection
Import-PSSession $Session
Remove-PSSession $Session
Actualizamos el buzón.
Start-ManagedFolderAssistant -Identity aliasdelbuzón