Add option to suppress Outlook security prompt

New setting "Outlook-Sicherheitsabfrage automatisch erlauben"
sets registry keys under HKCU\Policies\Microsoft\Office\16.0\
Outlook\Security to auto-approve Object Model Guard prompts.

Applied at app startup and when saving settings. Disabling the
option removes the registry values (back to Outlook default).
Works with all Outlook versions (2016-2024, same registry path).
No admin rights needed (HKCU).

Outlook must be restarted after changing this setting.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/StarfaceOutlookSync/Models/UserSettings.cs

@@ -1,5 +1,6 @@
 using System;
 using System.IO;
+using Microsoft.Win32;
 using Newtonsoft.Json;
 
 namespace StarfaceOutlookSync.Models
@@ -8,6 +9,7 @@ namespace StarfaceOutlookSync.Models
     {
         public bool StartMinimized { get; set; } = false;
         public bool SyncOnStart { get; set; } = false;
+        public bool AutoAcceptOutlookPrompt { get; set; } = false;
 
         private static readonly string SettingsFile = Path.Combine(
             Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData),
@@ -33,6 +35,45 @@ namespace StarfaceOutlookSync.Models
                 File.WriteAllText(SettingsFile, JsonConvert.SerializeObject(this, Formatting.Indented));
             }
             catch { }
+
+            ApplyOutlookSecuritySetting();
+        }
+
+        public void ApplyOutlookSecuritySetting()
+        {
+            try
+            {
+                var regPath = @"Software\Policies\Microsoft\Office\16.0\Outlook\Security";
+
+                if (AutoAcceptOutlookPrompt)
+                {
+                    // Alle Outlook Object Model Guard Prompts unterdruecken
+                    var key = Registry.CurrentUser.CreateSubKey(regPath);
+                    key.SetValue("ObjectModelGuard", 2, RegistryValueKind.DWord);
+                    key.SetValue("PromptOOMAddressBookAccess", 2, RegistryValueKind.DWord);
+                    key.SetValue("PromptOOMAddressInformationAccess", 2, RegistryValueKind.DWord);
+                    key.SetValue("AdminSecurityMode", 3, RegistryValueKind.DWord);
+                    key.Close();
+                }
+                else
+                {
+                    // Zurueck auf Standard (Werte loeschen)
+                    try
+                    {
+                        var key = Registry.CurrentUser.OpenSubKey(regPath, true);
+                        if (key != null)
+                        {
+                            try { key.DeleteValue("ObjectModelGuard"); } catch { }
+                            try { key.DeleteValue("PromptOOMAddressBookAccess"); } catch { }
+                            try { key.DeleteValue("PromptOOMAddressInformationAccess"); } catch { }
+                            try { key.DeleteValue("AdminSecurityMode"); } catch { }
+                            key.Close();
+                        }
+                    }
+                    catch { }
+                }
+            }
+            catch { }
         }
     }
 }

src/StarfaceOutlookSync/UI/MainForm.cs

@@ -31,8 +31,10 @@ namespace StarfaceOutlookSync.UI
             SetupAutoSync();
             RefreshProfileList();
 
-            // Minimiert starten falls in Einstellungen aktiviert
+            // Einstellungen laden und anwenden
             var settings = UserSettings.Load();
+            settings.ApplyOutlookSecuritySetting();
+
             if (settings.StartMinimized)
             {
                 WindowState = FormWindowState.Minimized;

src/StarfaceOutlookSync/UI/SettingsForm.cs

@@ -6,7 +6,7 @@ namespace StarfaceOutlookSync.UI
 {
     public class SettingsForm : Form
     {
-        private CheckBox _chkStartMinimized, _chkSyncOnStart;
+        private CheckBox _chkStartMinimized, _chkSyncOnStart, _chkAutoAcceptOutlook;
         private Button _btnSave, _btnCancel;
         private readonly UserSettings _settings;
 
@@ -19,7 +19,7 @@ namespace StarfaceOutlookSync.UI
         private void InitializeComponent()
         {
             Text = "Einstellungen";
-            Size = new Size(350, 210);
+            Size = new Size(380, 250);
             FormBorderStyle = FormBorderStyle.FixedDialog;
             MaximizeBox = false;
             MinimizeBox = false;
@@ -40,20 +40,27 @@ namespace StarfaceOutlookSync.UI
                 Checked = _settings.SyncOnStart
             };
 
+            _chkAutoAcceptOutlook = new CheckBox
+            {
+                Text = "Outlook-Sicherheitsabfrage automatisch erlauben",
+                Left = 20, Top = 80, AutoSize = true,
+                Checked = _settings.AutoAcceptOutlookPrompt
+            };
+
             _btnSave = new Button
             {
-                Text = "Speichern", Left = 80, Top = 130, Width = 85, Height = 28,
+                Text = "Speichern", Left = 95, Top = 160, Width = 85, Height = 28,
                 DialogResult = DialogResult.None
             };
             _btnSave.Click += (s, e) => Save();
 
             _btnCancel = new Button
             {
-                Text = "Abbrechen", Left = 174, Top = 130, Width = 85, Height = 28,
+                Text = "Abbrechen", Left = 189, Top = 160, Width = 85, Height = 28,
                 DialogResult = DialogResult.Cancel
             };
 
-            Controls.AddRange(new Control[] { _chkStartMinimized, _chkSyncOnStart, _btnSave, _btnCancel });
+            Controls.AddRange(new Control[] { _chkStartMinimized, _chkSyncOnStart, _chkAutoAcceptOutlook, _btnSave, _btnCancel });
             AcceptButton = _btnSave;
             CancelButton = _btnCancel;
         }
@@ -62,6 +69,7 @@ namespace StarfaceOutlookSync.UI
         {
             _settings.StartMinimized = _chkStartMinimized.Checked;
             _settings.SyncOnStart = _chkSyncOnStart.Checked;
+            _settings.AutoAcceptOutlookPrompt = _chkAutoAcceptOutlook.Checked;
             _settings.Save();
             DialogResult = DialogResult.OK;
             Close();