In EWS Managed API is it easy to create an appointment for a specific user:
ExchangeService service = new ExchangeService();
service.Credentials = new NetworkCre
I know this has been answered but in answer to @Aamir's comment you can do this using delegates I've just done it for a project I'm working on.
As @matt suggested in his answer you can amend the save method of the appointment to point to the other users folder which in this case would be Calendar.
Code would look as below
Appointment appointment = new Appointment(service);
appointment.Subject = "Testing";
appointment.Start = DateTime.Now;
appointment.End = appointment.Start.AddHours(1);
appointment.Save(new FolderId(WellKnownFolderName.Calendar, new Mailbox(_EmailAddress)));
Hope that helps