Estoy usando EWS 1.2 para enviar citas. Al crear nuevas citas, TimeZone se muestra correctamente en el correo de notificación, pero al actualizar la misma cita, se restablece TimeZone a UTC.

¿Alguien podría ayudarme a solucionar este problema?

Aquí hay un código de muestra para replicar el problema:

ExchangeService service = new ExchangeService(ExchangeVersion.Exchange2010_SP1, TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time"));
service.Credentials = new WebCredentials("ews_calendar", PASSWORD, "acme");
service.Url = new Uri("https://acme.com/EWS/Exchange.asmx");

Appointment newAppointment = new Appointment(service);
newAppointment.Subject = "Test Subject";
newAppointment.Body = "Test Body";
newAppointment.Start = new DateTime(2012, 03, 27, 17, 00, 0);
newAppointment.End = newAppointment.Start.AddMinutes(30);
newAppointment.RequiredAttendees.Add("[email protected]");

//Attendees get notification mail for this appointment using (UTC-05:00) Eastern Time (US & Canada) timezone
//Here is the notification content received by attendees:
//When: Tuesday, March 27, 2012 5:00 PM-5:30 PM. (UTC-05:00) Eastern Time (US & Canada)
newAppointment.Save(SendInvitationsMode.SendToAllAndSaveCopy);

// Pull existing appointment
string itemId = newAppointment.Id.ToString();

Appointment existingAppointment = Appointment.Bind(service, new ItemId(itemId));

//Attendees get notification mail for this appointment using UTC timezone
//Here is the notification content received by attendees:
//When: Tuesday, March 27, 2012 11:00 PM-11:30 PM. UTC
existingAppointment.Update(ConflictResolutionMode.AlwaysOverwrite, SendInvitationsOrCancellationsMode.SendToAllAndSaveCopy);