Create appointments in Outlook calenders of employees using C# and Exchange 2019

Question

I can't show any code here yet, because i'm still analyzing if it is possible to realize this.

In our company we have a virtual system to make and manage leave applications. I should now check if it would be possible to enter an approved vacation in the Outlook calendar of the applicant.

I would need a central solution which remotely accesses the calendar and enters the appointments. We currently use the on premise solution of Mircosoft Exchange 2019 and Office 365.

During my research I came across EWS but it seems that Exchange 2019 does not support it anymore. Is there possibly another solution which I could use? Basically I would like to realize a solution with C# but I would also be able to realize a Powershell or Java solution. But most of the time I did not find a real solution.

Most of the time the examples are always local on the machines or using an older Exchange Server like 2013. I haven't found reliable information for 2019 yet. I hope someone here can help me or give me a hint. Or it would also be helpful to say if it is not possible.

Best regards!

---

I am currently working on a solution. I will post the code when I am successfull!**

Answer 1

I did choose a little bit different approach but I was able to make it fully work. I now can create events and delete them if needed.

    public void UpdateCalender()
    {
        ExchangeService Service = new ExchangeService(ExchangeVersion.Exchange2013_SP1);
        Uri Url = new Uri("https://localmaildomain.sys/EWS/Exchange.asmx");
        Service.Url =  Url;
        Service.Credentials = new NetworkCredential("service_user","service_password");

        Folder inboxFolder = Folder.Bind(Service, new FolderId(WellKnownFolderName.Calendar, Temp.UserMail));

        foreach (var entry in Temp.Positions)
        {
            if (!entry.Storno)
            {
                try
                {
                    Appointment appointment = new Appointment(Service);
                    appointment.Subject = $"Urlaub/Vacation ({entry.Type})";
                    appointment.Body = $"{entry.Comment}";
                    appointment.IsAllDayEvent = true;
                    appointment.Start = entry.Date.AddSeconds(1);
                    appointment.End = entry.Date.AddSeconds(1);
                    appointment.LegacyFreeBusyStatus = LegacyFreeBusyStatus.OOF;
                    appointment.Save(inboxFolder.Id, SendInvitationsMode.SendToNone);
                }
                catch (Exception Ex)
                {
                    Console.WriteLine($"Calender item could not be created! Exception: {Ex.ToString()}");
                }
            }
            else
            {
                CalendarView view = new CalendarView(entry.Date, entry.Date);
                FindItemsResults<Appointment> results = Service.FindAppointments(inboxFolder.Id,view);

                foreach (var appointment in results)
                {
                    if (appointment.Subject == $"Urlaub/Vacation ({entry.Type})" && appointment.Start == entry.Date)
                    {
                        try
                        {
                            appointment.Delete(DeleteMode.MoveToDeletedItems);
                        }
                        catch(Exception Ex)
                        {
                            Console.WriteLine($"Calender item could not be deleted! Exception: {Ex.ToString()}");
                        }
                        break;
                    }
                }
            }
        }
    }