Error 404 during synchronization CRM Online to Exchange Online

Hello,

we had this error when configuring an emailbox of users MS CRM Online to Outlook Exchange.
Anybody fixed this problem?

ActivityId: 2810e04a-f6fb-49ac-be91-5a4cedeff3d8
>Error : System.Net.WebException: The request failed with HTTP status 404: Not Found.
   at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)
   at System.Web.Services.Protocols.SoapHttpClientProtocol.EndInvoke(IAsyncResult asyncResult)
   at Microsoft.Crm.Asynchronous.EmailConnector.ExchangeServiceBinding.EndCreateItem(IAsyncResult asyncResult)
   at Microsoft.Crm.Asynchronous.EmailConnector.ExchangeOutgoingEmailProvider.EndCreateItem()