Release v0.0.0.7

The NuGet package Microsoft.Office.Interop.Outlook v15 tried to
load Office v15 PIA which fails on Office 2016/2019/2024 (v16).

Switch to dynamic COM (late binding) which works with ANY Outlook
Classic version without needing a specific Interop DLL. All Outlook
properties and methods are accessed via dynamic dispatch.

Also use 1-based COM collection indexing instead of foreach to
avoid COM enumerator issues.

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

installer/setup.iss

@@ -2,7 +2,7 @@
 ; Erfordert Inno Setup 6.x (https://jrsoftware.org/isinfo.php)
 
 #define MyAppName "Starface Outlook Sync"
-#define MyAppVersion "0.0.0.2"
+#define MyAppVersion "0.0.0.7"
 #define MyAppPublisher "HackerSoft - Hacker-Net Telekommunikation"
 #define MyAppURL "https://www.hacker-net.de"
 #define MyAppExeName "StarfaceOutlookSync.exe"

src/StarfaceOutlookSync/Models/UserSettings.cs

@@ -0,0 +1,37 @@
+using System;
+using System.IO;
+using Newtonsoft.Json;
+
+namespace StarfaceOutlookSync.Models
+{
+    public class UserSettings
+    {
+        public bool StartMinimized { get; set; } = false;
+
+        private static readonly string SettingsFile = Path.Combine(
+            Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData),
+            "StarfaceOutlookSync", "settings.json");
+
+        public static UserSettings Load()
+        {
+            try
+            {
+                if (File.Exists(SettingsFile))
+                    return JsonConvert.DeserializeObject<UserSettings>(File.ReadAllText(SettingsFile))
+                           ?? new UserSettings();
+            }
+            catch { }
+            return new UserSettings();
+        }
+
+        public void Save()
+        {
+            try
+            {
+                Directory.CreateDirectory(Path.GetDirectoryName(SettingsFile));
+                File.WriteAllText(SettingsFile, JsonConvert.SerializeObject(this, Formatting.Indented));
+            }
+            catch { }
+        }
+    }
+}

src/StarfaceOutlookSync/Services/OutlookContactsService.cs

@@ -2,44 +2,75 @@ using System;
 using System.Collections.Generic;
 using System.Runtime.InteropServices;
 using StarfaceOutlookSync.Models;
-using Outlook = Microsoft.Office.Interop.Outlook;
 
 namespace StarfaceOutlookSync.Services
 {
+    /// <summary>
+    /// Zugriff auf Outlook-Kontakte per dynamic COM.
+    /// Funktioniert mit jeder Outlook Classic Version (2013-2024)
+    /// ohne Abhaengigkeit von einer bestimmten Interop-DLL.
+    /// </summary>
     public class OutlookContactsService : IDisposable
     {
-        private Outlook.Application _outlookApp;
+        private dynamic _outlookApp;
         private bool _weStartedOutlook;
 
-        // Marshal.GetActiveObject existiert nicht in .NET 8, daher P/Invoke
+        // OlDefaultFolders.olFolderContacts = 10
+        private const int OlFolderContacts = 10;
+        // OlItemType.olContactItem = 2
+        private const int OlContactItem = 2;
+
         [DllImport("oleaut32.dll", PreserveSig = false)]
-        private static extern void GetActiveObject([MarshalAs(UnmanagedType.LPStruct)] Guid rclsid, IntPtr pvReserved, [MarshalAs(UnmanagedType.IUnknown)] out object ppunk);
+        private static extern void GetActiveObject(
+            [MarshalAs(UnmanagedType.LPStruct)] Guid rclsid,
+            IntPtr pvReserved,
+            [MarshalAs(UnmanagedType.IUnknown)] out object ppunk);
 
         private static object GetActiveComObject(string progId)
         {
-            var clsid = Type.GetTypeFromProgID(progId, true).GUID;
+            var type = Type.GetTypeFromProgID(progId, false);
-            GetActiveObject(clsid, IntPtr.Zero, out var obj);
+            if (type == null) return null;
+            GetActiveObject(type.GUID, IntPtr.Zero, out var obj);
             return obj;
         }
 
-        private Outlook.Application GetOutlookApp()
+        private dynamic GetOutlookApp()
         {
             if (_outlookApp != null) return _outlookApp;
 
+            // Versuch 1: Laufende Outlook-Instanz finden
             try
             {
-                // Versuche laufende Outlook-Instanz zu finden
+                var obj = GetActiveComObject("Outlook.Application");
-                _outlookApp = (Outlook.Application)GetActiveComObject("Outlook.Application");
+                if (obj != null)
-                _weStartedOutlook = false;
+                {
-            }
+                    _outlookApp = obj;
-            catch
+                    _weStartedOutlook = false;
-            {
+                    return _outlookApp;
-                // Outlook starten falls nicht laufend
+                }
-                _outlookApp = new Outlook.Application();
-                _weStartedOutlook = true;
             }
+            catch { }
 
-            return _outlookApp;
+            // Versuch 2: Outlook per COM starten
+            try
+            {
+                var outlookType = Type.GetTypeFromProgID("Outlook.Application", false);
+                if (outlookType != null)
+                {
+                    _outlookApp = Activator.CreateInstance(outlookType);
+                    _weStartedOutlook = true;
+                    return _outlookApp;
+                }
+            }
+            catch { }
+
+            throw new InvalidOperationException(
+                "Outlook Classic konnte nicht gefunden werden.\n\n" +
+                "Moegliche Ursachen:\n" +
+                "- Outlook Classic ist nicht installiert\n" +
+                "- Outlook Classic ist nicht gestartet\n" +
+                "- Das neue Outlook wird verwendet (wird noch nicht unterstuetzt)\n\n" +
+                "Bitte Outlook Classic starten und erneut versuchen.");
         }
 
         public List<string> GetContactFolderPaths()
@@ -50,128 +81,164 @@ namespace StarfaceOutlookSync.Services
                 var app = GetOutlookApp();
                 var ns = app.GetNamespace("MAPI");
 
-                // Standard-Kontaktordner
+                // Alle Stores durchgehen
-                var defaultFolder = ns.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderContacts);
+                var stores = ns.Stores;
-                folders.Add(defaultFolder.FolderPath);
+                for (int i = 1; i <= (int)stores.Count; i++)
-
-                // Unterordner
-                AddSubFolders(defaultFolder, folders);
-
-                // Weitere Kontaktordner in anderen Stores
-                foreach (Outlook.Store store in ns.Stores)
                 {
                     try
                     {
+                        var store = stores[i];
                         var rootFolder = store.GetRootFolder();
-                        FindContactFolders(rootFolder, folders);
+                        FindContactFoldersRecursive(rootFolder, folders);
+                        Marshal.ReleaseComObject(rootFolder);
+                        Marshal.ReleaseComObject(store);
+                    }
+                    catch (Exception ex)
+                    {
+                        System.Diagnostics.Debug.WriteLine($"Error scanning store {i}: {ex.Message}");
+                    }
+                }
+
+                // Falls nichts gefunden, Standard-Kontaktordner als Fallback
+                if (folders.Count == 0)
+                {
+                    try
+                    {
+                        var defaultFolder = ns.GetDefaultFolder(OlFolderContacts);
+                        folders.Add((string)defaultFolder.FolderPath);
+                        Marshal.ReleaseComObject(defaultFolder);
                     }
                     catch { }
                 }
 
+                Marshal.ReleaseComObject(stores);
                 Marshal.ReleaseComObject(ns);
             }
             catch (Exception ex)
             {
                 System.Diagnostics.Debug.WriteLine($"Error getting folders: {ex.Message}");
+                throw;
             }
 
             return folders;
         }
 
-        private void AddSubFolders(Outlook.MAPIFolder folder, List<string> paths)
+        private void FindContactFoldersRecursive(dynamic folder, List<string> paths)
         {
-            foreach (Outlook.MAPIFolder sub in folder.Folders)
+            try
             {
-                if (sub.DefaultItemType == Outlook.OlItemType.olContactItem)
+                if ((int)folder.DefaultItemType == OlContactItem)
                 {
-                    if (!paths.Contains(sub.FolderPath))
+                    string path = folder.FolderPath;
-                        paths.Add(sub.FolderPath);
+                    if (!paths.Contains(path))
-                    AddSubFolders(sub, paths);
+                        paths.Add(path);
                 }
+
+                var subFolders = folder.Folders;
+                for (int i = 1; i <= (int)subFolders.Count; i++)
+                {
+                    try
+                    {
+                        var sub = subFolders[i];
+                        FindContactFoldersRecursive(sub, paths);
+                        Marshal.ReleaseComObject(sub);
+                    }
+                    catch { }
+                }
+                Marshal.ReleaseComObject(subFolders);
+            }
+            catch (Exception ex)
+            {
+                System.Diagnostics.Debug.WriteLine($"Error scanning folder: {ex.Message}");
             }
         }
 
-        private void FindContactFolders(Outlook.MAPIFolder folder, List<string> paths)
+        private dynamic GetFolderByPath(string folderPath)
-        {
-            if (folder.DefaultItemType == Outlook.OlItemType.olContactItem)
-            {
-                if (!paths.Contains(folder.FolderPath))
-                    paths.Add(folder.FolderPath);
-            }
-
-            foreach (Outlook.MAPIFolder sub in folder.Folders)
-            {
-                FindContactFolders(sub, paths);
-            }
-        }
-
-        private Outlook.MAPIFolder GetFolderByPath(string folderPath)
         {
             var app = GetOutlookApp();
             var ns = app.GetNamespace("MAPI");
 
-            // Standard-Kontaktordner als Fallback
             if (string.IsNullOrEmpty(folderPath))
-                return ns.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderContacts);
+                return ns.GetDefaultFolder(OlFolderContacts);
 
             try
             {
-                // Pfad durchlaufen
                 var parts = folderPath.Split(new[] { '\\' }, StringSplitOptions.RemoveEmptyEntries);
-                Outlook.MAPIFolder current = null;
+                dynamic current = null;
 
-                foreach (Outlook.Store store in ns.Stores)
+                var stores = ns.Stores;
+                for (int i = 1; i <= (int)stores.Count; i++)
                 {
-                    if (store.GetRootFolder().Name == parts[0] ||
+                    var store = stores[i];
-                        store.GetRootFolder().FolderPath.TrimStart('\\') == parts[0])
+                    var root = store.GetRootFolder();
+                    string rootName = root.Name;
+
+                    if (rootName == parts[0])
                     {
-                        current = store.GetRootFolder();
+                        current = root;
                         break;
                     }
+                    Marshal.ReleaseComObject(root);
+                    Marshal.ReleaseComObject(store);
                 }
+                Marshal.ReleaseComObject(stores);
 
                 if (current == null)
-                    return ns.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderContacts);
+                    return ns.GetDefaultFolder(OlFolderContacts);
 
                 for (int i = 1; i < parts.Length; i++)
                 {
                     bool found = false;
-                    foreach (Outlook.MAPIFolder sub in current.Folders)
+                    var subFolders = current.Folders;
+                    for (int j = 1; j <= (int)subFolders.Count; j++)
                     {
-                        if (sub.Name == parts[i])
+                        var sub = subFolders[j];
+                        if ((string)sub.Name == parts[i])
                         {
                             current = sub;
                             found = true;
                             break;
                         }
+                        Marshal.ReleaseComObject(sub);
                     }
+                    Marshal.ReleaseComObject(subFolders);
+
                     if (!found)
-                        return ns.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderContacts);
+                        return ns.GetDefaultFolder(OlFolderContacts);
                 }
 
                 return current;
             }
             catch
             {
-                return ns.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderContacts);
+                return ns.GetDefaultFolder(OlFolderContacts);
             }
         }
 
         public List<UnifiedContact> GetContacts(string folderPath)
         {
             var contacts = new List<UnifiedContact>();
-
             try
             {
                 var folder = GetFolderByPath(folderPath);
                 var items = folder.Items;
 
-                foreach (var item in items)
+                for (int i = 1; i <= (int)items.Count; i++)
                 {
-                    if (item is Outlook.ContactItem ci)
+                    dynamic item = null;
+                    try
                     {
-                        contacts.Add(MapFromOutlook(ci));
+                        item = items[i];
-                        Marshal.ReleaseComObject(ci);
+                        // Nur ContactItems verarbeiten (Class = 40 = olContact)
+                        if ((int)item.Class == 40)
+                        {
+                            contacts.Add(MapFromOutlook(item));
+                        }
+                    }
+                    catch { }
+                    finally
+                    {
+                        if (item != null) Marshal.ReleaseComObject(item);
                     }
                 }
 
@@ -191,7 +258,8 @@ namespace StarfaceOutlookSync.Services
             try
             {
                 var folder = GetFolderByPath(folderPath);
-                var ci = (Outlook.ContactItem)folder.Items.Add(Outlook.OlItemType.olContactItem);
+                var items = folder.Items;
+                dynamic ci = items.Add(OlContactItem);
 
                 MapToOutlook(contact, ci);
                 ci.Save();
@@ -199,6 +267,7 @@ namespace StarfaceOutlookSync.Services
                 contact.OutlookEntryId = ci.EntryID;
 
                 Marshal.ReleaseComObject(ci);
+                Marshal.ReleaseComObject(items);
                 Marshal.ReleaseComObject(folder);
 
                 return contact;
@@ -216,7 +285,7 @@ namespace StarfaceOutlookSync.Services
             {
                 var app = GetOutlookApp();
                 var ns = app.GetNamespace("MAPI");
-                var ci = (Outlook.ContactItem)ns.GetItemFromID(entryId);
+                dynamic ci = ns.GetItemFromID(entryId);
 
                 MapToOutlook(contact, ci);
                 ci.Save();
@@ -239,7 +308,7 @@ namespace StarfaceOutlookSync.Services
             {
                 var app = GetOutlookApp();
                 var ns = app.GetNamespace("MAPI");
-                var ci = (Outlook.ContactItem)ns.GetItemFromID(entryId);
+                dynamic ci = ns.GetItemFromID(entryId);
 
                 ci.Delete();
                 Marshal.ReleaseComObject(ci);
@@ -254,36 +323,46 @@ namespace StarfaceOutlookSync.Services
             }
         }
 
-        private UnifiedContact MapFromOutlook(Outlook.ContactItem ci)
+        private UnifiedContact MapFromOutlook(dynamic ci)
         {
             return new UnifiedContact
             {
-                OutlookEntryId = ci.EntryID ?? "",
+                OutlookEntryId = (string)(ci.EntryID ?? ""),
-                FirstName = ci.FirstName ?? "",
+                FirstName = (string)(ci.FirstName ?? ""),
-                LastName = ci.LastName ?? "",
+                LastName = (string)(ci.LastName ?? ""),
-                Company = ci.CompanyName ?? "",
+                Company = (string)(ci.CompanyName ?? ""),
-                JobTitle = ci.JobTitle ?? "",
+                JobTitle = (string)(ci.JobTitle ?? ""),
-                Email = ci.Email1Address ?? "",
+                Email = (string)(ci.Email1Address ?? ""),
-                EmailSecondary = ci.Email2Address ?? "",
+                EmailSecondary = (string)(ci.Email2Address ?? ""),
-                PhoneWork = ci.BusinessTelephoneNumber ?? "",
+                PhoneWork = (string)(ci.BusinessTelephoneNumber ?? ""),
-                PhoneMobile = ci.MobileTelephoneNumber ?? "",
+                PhoneMobile = (string)(ci.MobileTelephoneNumber ?? ""),
-                PhoneHome = ci.HomeTelephoneNumber ?? "",
+                PhoneHome = (string)(ci.HomeTelephoneNumber ?? ""),
-                Fax = ci.BusinessFaxNumber ?? "",
+                Fax = (string)(ci.BusinessFaxNumber ?? ""),
-                Street = ci.BusinessAddressStreet ?? "",
+                Street = (string)(ci.BusinessAddressStreet ?? ""),
-                City = ci.BusinessAddressCity ?? "",
+                City = (string)(ci.BusinessAddressCity ?? ""),
-                PostalCode = ci.BusinessAddressPostalCode ?? "",
+                PostalCode = (string)(ci.BusinessAddressPostalCode ?? ""),
-                State = ci.BusinessAddressState ?? "",
+                State = (string)(ci.BusinessAddressState ?? ""),
-                Country = ci.BusinessAddressCountry ?? "",
+                Country = (string)(ci.BusinessAddressCountry ?? ""),
-                Website = ci.WebPage ?? "",
+                Website = (string)(ci.WebPage ?? ""),
-                Notes = ci.Body ?? "",
+                Notes = (string)(ci.Body ?? ""),
-                Salutation = ci.Title ?? "",
+                Salutation = (string)(ci.Title ?? ""),
-                Title = ci.Suffix ?? "",
+                Birthday = GetBirthdayString(ci)
-                Birthday = ci.Birthday != DateTime.MinValue && ci.Birthday.Year > 1900
-                    ? ci.Birthday.ToString("yyyy-MM-dd") : ""
             };
         }
 
-        private void MapToOutlook(UnifiedContact contact, Outlook.ContactItem ci)
+        private string GetBirthdayString(dynamic ci)
+        {
+            try
+            {
+                DateTime bday = ci.Birthday;
+                if (bday.Year > 1900 && bday != DateTime.MinValue)
+                    return bday.ToString("yyyy-MM-dd");
+            }
+            catch { }
+            return "";
+        }
+
+        private void MapToOutlook(UnifiedContact contact, dynamic ci)
         {
             ci.FirstName = contact.FirstName;
             ci.LastName = contact.LastName;
@@ -320,7 +399,7 @@ namespace StarfaceOutlookSync.Services
                 {
                     try { _outlookApp.Quit(); } catch { }
                 }
-                Marshal.ReleaseComObject(_outlookApp);
+                try { Marshal.ReleaseComObject(_outlookApp); } catch { }
                 _outlookApp = null;
             }
         }

src/StarfaceOutlookSync/StarfaceOutlookSync.csproj

@@ -7,9 +7,9 @@
     <AssemblyTitle>Starface Outlook Sync</AssemblyTitle>
     <Company>HackerSoft - Hacker-Net Telekommunikation</Company>
     <Product>Starface Outlook Sync</Product>
-    <Version>0.0.0.2</Version>
+    <Version>0.0.0.7</Version>
-    <AssemblyVersion>0.0.0.2</AssemblyVersion>
+    <AssemblyVersion>0.0.0.7</AssemblyVersion>
-    <FileVersion>0.0.0.2</FileVersion>
+    <FileVersion>0.0.0.7</FileVersion>
     <Description>Synchronisiert Outlook-Kontakte mit Starface Telefonanlage</Description>
     <Copyright>Stefan Hacker - HackerSoft</Copyright>
     <RuntimeIdentifier>win-x64</RuntimeIdentifier>
@@ -19,7 +19,6 @@
 
   <ItemGroup>
     <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
-    <PackageReference Include="Microsoft.Office.Interop.Outlook" Version="15.0.4797.1004" />
   </ItemGroup>
 
 </Project>

src/StarfaceOutlookSync/UI/AboutForm.cs

@@ -27,7 +27,7 @@ namespace StarfaceOutlookSync.UI
 
             var lblVersion = new Label
             {
-                Text = "Version 0.0.0.2",
+                Text = "Version 0.0.0.7",
                 Left = 0, Top = 56, Width = 340, Height = 20,
                 TextAlign = ContentAlignment.MiddleCenter,
                 ForeColor = Color.Gray

src/StarfaceOutlookSync/UI/MainForm.cs

@@ -18,7 +18,7 @@ namespace StarfaceOutlookSync.UI
         private NotifyIcon _trayIcon;
         private ContextMenuStrip _trayMenu;
         private ListView _profileList;
-        private Button _btnNew, _btnEdit, _btnDelete, _btnSync, _btnInfo;
+        private Button _btnNew, _btnEdit, _btnDelete, _btnSync, _btnSettings, _btnInfo;
         private StatusStrip _statusBar;
         private ToolStripStatusLabel _statusLabel;
         private Timer _autoSyncTimer;
@@ -29,6 +29,30 @@ namespace StarfaceOutlookSync.UI
             SetupTrayIcon();
             SetupAutoSync();
             RefreshProfileList();
+
+            // Minimiert starten falls in Einstellungen aktiviert
+            var settings = UserSettings.Load();
+            if (settings.StartMinimized)
+            {
+                WindowState = FormWindowState.Minimized;
+                ShowInTaskbar = false;
+                Visible = false;
+            }
+        }
+
+        protected override void SetVisibleCore(bool value)
+        {
+            // Beim ersten Anzeigen pruefen ob minimiert gestartet werden soll
+            if (!IsHandleCreated)
+            {
+                var settings = UserSettings.Load();
+                if (settings.StartMinimized)
+                {
+                    CreateHandle();
+                    value = false;
+                }
+            }
+            base.SetVisibleCore(value);
         }
 
         private void InitializeComponent()
@@ -76,10 +100,13 @@ namespace StarfaceOutlookSync.UI
             _btnSync = new Button { Text = "Jetzt synchronisieren", Width = 150, Height = 30 };
             _btnSync.Click += async (s, e) => await SyncSelectedProfile();
 
+            _btnSettings = new Button { Text = "Einstellungen", Width = 100, Height = 30 };
+            _btnSettings.Click += (s, e) => ShowSettings();
+
             _btnInfo = new Button { Text = "Info", Width = 50, Height = 30 };
             _btnInfo.Click += (s, e) => ShowAbout();
 
-            buttonPanel.Controls.AddRange(new Control[] { _btnNew, _btnEdit, _btnDelete, _btnSync, _btnInfo });
+            buttonPanel.Controls.AddRange(new Control[] { _btnNew, _btnEdit, _btnDelete, _btnSync, _btnSettings, _btnInfo });
 
             // Statusbar
             _statusBar = new StatusStrip();
@@ -283,6 +310,14 @@ namespace StarfaceOutlookSync.UI
                 _statusLabel.Text = text;
         }
 
+        private void ShowSettings()
+        {
+            using (var settings = new SettingsForm())
+            {
+                settings.ShowDialog(this);
+            }
+        }
+
         private void ShowAbout()
         {
             using (var about = new AboutForm())

src/StarfaceOutlookSync/UI/OutlookFolderBrowserForm.cs

@@ -0,0 +1,125 @@
+using System;
+using System.Drawing;
+using System.Windows.Forms;
+using System.Collections.Generic;
+
+namespace StarfaceOutlookSync.UI
+{
+    public class OutlookFolderBrowserForm : Form
+    {
+        private TreeView _tree;
+        private Button _btnOk, _btnCancel;
+        public string SelectedFolderPath { get; private set; } = "";
+        public string SelectedFolderName { get; private set; } = "";
+
+        public OutlookFolderBrowserForm(List<string> folderPaths, string currentSelection)
+        {
+            InitializeComponent();
+            BuildTree(folderPaths, currentSelection);
+        }
+
+        private void InitializeComponent()
+        {
+            Text = "Outlook-Ordner waehlen";
+            Size = new Size(400, 450);
+            FormBorderStyle = FormBorderStyle.FixedDialog;
+            MaximizeBox = false;
+            MinimizeBox = false;
+            StartPosition = FormStartPosition.CenterParent;
+            Font = new Font("Segoe UI", 9);
+
+            var lblInfo = new Label
+            {
+                Text = "Bitte waehlen Sie den Outlook-Kontaktordner fuer die Synchronisation:",
+                Left = 12, Top = 12, Width = 360, Height = 36
+            };
+
+            _tree = new TreeView
+            {
+                Left = 12, Top = 52, Width = 360, Height = 310,
+                HideSelection = false,
+                ShowLines = true,
+                ShowPlusMinus = true,
+                ShowRootLines = true
+            };
+            _tree.DoubleClick += (s, e) => { if (_tree.SelectedNode?.Tag != null) SelectAndClose(); };
+
+            _btnOk = new Button
+            {
+                Text = "OK", Left = 210, Top = 372, Width = 75, Height = 28,
+                DialogResult = DialogResult.None
+            };
+            _btnOk.Click += (s, e) => SelectAndClose();
+
+            _btnCancel = new Button
+            {
+                Text = "Abbrechen", Left = 292, Top = 372, Width = 80, Height = 28,
+                DialogResult = DialogResult.Cancel
+            };
+
+            Controls.AddRange(new Control[] { lblInfo, _tree, _btnOk, _btnCancel });
+            AcceptButton = _btnOk;
+            CancelButton = _btnCancel;
+        }
+
+        private void BuildTree(List<string> folderPaths, string currentSelection)
+        {
+            _tree.Nodes.Clear();
+            var nodeMap = new Dictionary<string, TreeNode>();
+
+            foreach (var path in folderPaths)
+            {
+                // Pfad: \\Store\Kontakte\Unterordner
+                var parts = path.TrimStart('\\').Split('\\');
+                string runningPath = "";
+                TreeNode parent = null;
+
+                for (int i = 0; i < parts.Length; i++)
+                {
+                    runningPath += "\\" + parts[i];
+
+                    if (!nodeMap.ContainsKey(runningPath))
+                    {
+                        var node = new TreeNode(parts[i]);
+                        // Nur Blatt-Knoten oder bekannte Pfade sind waehlbar
+                        if (i == parts.Length - 1)
+                            node.Tag = path; // Vollstaendiger Pfad
+
+                        if (parent == null)
+                            _tree.Nodes.Add(node);
+                        else
+                            parent.Nodes.Add(node);
+
+                        nodeMap[runningPath] = node;
+
+                        // Aktuellen Ordner vorauswaehlen
+                        if (path == currentSelection)
+                        {
+                            _tree.SelectedNode = node;
+                            node.EnsureVisible();
+                        }
+                    }
+
+                    parent = nodeMap[runningPath];
+                }
+            }
+
+            _tree.ExpandAll();
+        }
+
+        private void SelectAndClose()
+        {
+            if (_tree.SelectedNode?.Tag == null)
+            {
+                MessageBox.Show("Bitte einen Kontaktordner waehlen.", "Hinweis",
+                    MessageBoxButtons.OK, MessageBoxIcon.Information);
+                return;
+            }
+
+            SelectedFolderPath = _tree.SelectedNode.Tag.ToString();
+            SelectedFolderName = _tree.SelectedNode.Text;
+            DialogResult = DialogResult.OK;
+            Close();
+        }
+    }
+}

src/StarfaceOutlookSync/UI/ProfileEditorForm.cs

@@ -15,14 +15,18 @@ namespace StarfaceOutlookSync.UI
         private readonly bool _isNew;
 
         // Controls
-        private TextBox _txtName, _txtHost, _txtPort, _txtLoginId, _txtPassword;
+        private TextBox _txtName, _txtHost, _txtPort, _txtLoginId, _txtPassword, _txtOutlookFolder;
         private CheckBox _chkSsl, _chkEnabled;
-        private ComboBox _cmbAddressBook, _cmbOutlookFolder, _cmbDirection;
+        private ComboBox _cmbAddressBook, _cmbDirection;
+        private Button _btnBrowseFolder;
         private NumericUpDown _numAutoSync;
         private Button _btnTest, _btnLoadBooks, _btnSave, _btnCancel;
         private Label _lblTestResult;
 
         private List<StarfaceAddressBook> _addressBooks = new List<StarfaceAddressBook>();
+        private List<string> _outlookFolderPaths = new List<string>();
+        private string _selectedOutlookPath = "";
+        private string _selectedOutlookName = "";
 
         public ProfileEditorForm(SyncProfile profile)
         {
@@ -87,8 +91,11 @@ namespace StarfaceOutlookSync.UI
             panel.Controls.Add(MakeSectionLabel("Outlook-Einstellungen", 12, y)); y += 26;
 
             panel.Controls.Add(MakeLabel("Kontakte-Ordner:", 12, y)); y += 22;
-            _cmbOutlookFolder = new ComboBox { Left = 12, Top = y, Width = 420, DropDownStyle = ComboBoxStyle.DropDownList };
+            _txtOutlookFolder = new TextBox { Left = 12, Top = y, Width = 330, ReadOnly = true, BackColor = SystemColors.Window };
-            panel.Controls.Add(_cmbOutlookFolder); y += 32;
+            _btnBrowseFolder = new Button { Text = "Durchsuchen...", Left = 348, Top = y - 1, Width = 84, Height = 24 };
+            _btnBrowseFolder.Click += (s, e) => BrowseOutlookFolder();
+            panel.Controls.Add(_txtOutlookFolder);
+            panel.Controls.Add(_btnBrowseFolder); y += 32;
 
             panel.Controls.Add(MakeLabel("Sync-Richtung:", 12, y)); y += 22;
             _cmbDirection = new ComboBox { Left = 12, Top = y, Width = 250, DropDownStyle = ComboBoxStyle.DropDownList };
@@ -132,18 +139,15 @@ namespace StarfaceOutlookSync.UI
             {
                 using (var outlook = new OutlookContactsService())
                 {
-                    var folders = outlook.GetContactFolderPaths();
+                    _outlookFolderPaths = outlook.GetContactFolderPaths();
-                    _cmbOutlookFolder.Items.Clear();
-                    foreach (var f in folders)
-                        _cmbOutlookFolder.Items.Add(f);
-                    if (folders.Count > 0)
-                        _cmbOutlookFolder.SelectedIndex = 0;
                 }
             }
-            catch
+            catch (Exception ex)
             {
-                _cmbOutlookFolder.Items.Add("\\\\Kontakte");
+                MessageBox.Show(
-                _cmbOutlookFolder.SelectedIndex = 0;
+                    $"Outlook-Kontaktordner konnten nicht geladen werden:\n{ex.Message}\n\nIst Outlook gestartet?",
+                    "Outlook-Verbindung", MessageBoxButtons.OK, MessageBoxIcon.Warning);
+                _outlookFolderPaths = new List<string>();
             }
 
             // Bestehende Werte laden
@@ -160,15 +164,10 @@ namespace StarfaceOutlookSync.UI
 
                 _cmbDirection.SelectedIndex = (int)_existingProfile.SyncDirection;
 
-                // Outlook-Ordner auswaehlen
+                // Outlook-Ordner
-                for (int i = 0; i < _cmbOutlookFolder.Items.Count; i++)
+                _selectedOutlookPath = _existingProfile.OutlookFolderPath;
-                {
+                _selectedOutlookName = _existingProfile.OutlookFolderName;
-                    if (_cmbOutlookFolder.Items[i].ToString() == _existingProfile.OutlookFolderPath)
+                _txtOutlookFolder.Text = _selectedOutlookPath;
-                    {
-                        _cmbOutlookFolder.SelectedIndex = i;
-                        break;
-                    }
-                }
 
                 // Adressbuch
                 if (_existingProfile.StarfaceAddressBook != null)
@@ -178,6 +177,26 @@ namespace StarfaceOutlookSync.UI
                     _cmbAddressBook.SelectedIndex = 0;
                 }
             }
+            else if (_outlookFolderPaths.Count > 0)
+            {
+                // Standard-Ordner vorauswaehlen
+                _selectedOutlookPath = _outlookFolderPaths[0];
+                _selectedOutlookName = _selectedOutlookPath.Substring(_selectedOutlookPath.LastIndexOf('\\') + 1);
+                _txtOutlookFolder.Text = _selectedOutlookPath;
+            }
+        }
+
+        private void BrowseOutlookFolder()
+        {
+            using (var browser = new OutlookFolderBrowserForm(_outlookFolderPaths, _selectedOutlookPath))
+            {
+                if (browser.ShowDialog(this) == DialogResult.OK)
+                {
+                    _selectedOutlookPath = browser.SelectedFolderPath;
+                    _selectedOutlookName = browser.SelectedFolderName;
+                    _txtOutlookFolder.Text = _selectedOutlookPath;
+                }
+            }
         }
 
         private StarfaceConnection GetConnection()
@@ -292,10 +311,12 @@ namespace StarfaceOutlookSync.UI
                 return;
             }
 
-            var selectedFolder = _cmbOutlookFolder.SelectedItem?.ToString() ?? "";
+            if (string.IsNullOrEmpty(_selectedOutlookPath))
-            var folderName = selectedFolder;
+            {
-            if (folderName.Contains("\\"))
+                MessageBox.Show("Bitte einen Outlook-Kontaktordner waehlen.",
-                folderName = folderName.Substring(folderName.LastIndexOf('\\') + 1);
+                    "Fehler", MessageBoxButtons.OK, MessageBoxIcon.Warning);
+                return;
+            }
 
             var profile = new SyncProfile
             {
@@ -303,8 +324,8 @@ namespace StarfaceOutlookSync.UI
                 Name = _txtName.Text.Trim(),
                 StarfaceConnection = GetConnection(),
                 StarfaceAddressBook = _addressBooks[_cmbAddressBook.SelectedIndex],
-                OutlookFolderPath = selectedFolder,
+                OutlookFolderPath = _selectedOutlookPath,
-                OutlookFolderName = folderName,
+                OutlookFolderName = _selectedOutlookName,
                 SyncDirection = (SyncDirection)_cmbDirection.SelectedIndex,
                 Enabled = _chkEnabled.Checked,
                 AutoSyncIntervalMinutes = (int)_numAutoSync.Value,

src/StarfaceOutlookSync/UI/SettingsForm.cs

@@ -0,0 +1,62 @@
+using System.Drawing;
+using System.Windows.Forms;
+using StarfaceOutlookSync.Models;
+
+namespace StarfaceOutlookSync.UI
+{
+    public class SettingsForm : Form
+    {
+        private CheckBox _chkStartMinimized;
+        private Button _btnSave, _btnCancel;
+        private readonly UserSettings _settings;
+
+        public SettingsForm()
+        {
+            _settings = UserSettings.Load();
+            InitializeComponent();
+        }
+
+        private void InitializeComponent()
+        {
+            Text = "Einstellungen";
+            Size = new Size(350, 180);
+            FormBorderStyle = FormBorderStyle.FixedDialog;
+            MaximizeBox = false;
+            MinimizeBox = false;
+            StartPosition = FormStartPosition.CenterParent;
+            Font = new Font("Segoe UI", 9);
+
+            _chkStartMinimized = new CheckBox
+            {
+                Text = "Minimiert starten (nur im System Tray)",
+                Left = 20, Top = 24, AutoSize = true,
+                Checked = _settings.StartMinimized
+            };
+
+            _btnSave = new Button
+            {
+                Text = "Speichern", Left = 80, Top = 100, Width = 85, Height = 28,
+                DialogResult = DialogResult.None
+            };
+            _btnSave.Click += (s, e) => Save();
+
+            _btnCancel = new Button
+            {
+                Text = "Abbrechen", Left = 174, Top = 100, Width = 85, Height = 28,
+                DialogResult = DialogResult.Cancel
+            };
+
+            Controls.AddRange(new Control[] { _chkStartMinimized, _btnSave, _btnCancel });
+            AcceptButton = _btnSave;
+            CancelButton = _btnCancel;
+        }
+
+        private void Save()
+        {
+            _settings.StartMinimized = _chkStartMinimized.Checked;
+            _settings.Save();
+            DialogResult = DialogResult.OK;
+            Close();
+        }
+    }
+}