diff --git a/src/StarfaceOutlookSync/UI/MainForm.cs b/src/StarfaceOutlookSync/UI/MainForm.cs
index 35170ffe..15778e24 100644
--- a/src/StarfaceOutlookSync/UI/MainForm.cs
+++ b/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, _btnSettings, _btnInfo;
+        private Button _btnNew, _btnEdit, _btnDelete, _btnSync, _btnReset, _btnSettings, _btnInfo;
         private StatusStrip _statusBar;
         private ToolStripStatusLabel _statusLabel;
         private Timer _autoSyncTimer;
@@ -97,16 +97,19 @@ namespace StarfaceOutlookSync.UI
             _btnDelete = new Button { Text = "Loeschen", Width = 80, Height = 30 };
             _btnDelete.Click += (s, e) => DeleteProfile();
 
-            _btnSync = new Button { Text = "Jetzt synchronisieren", Width = 150, Height = 30 };
+            _btnSync = new Button { Text = "Synchronisieren", Width = 110, Height = 30 };
             _btnSync.Click += async (s, e) => await SyncSelectedProfile();
 
-            _btnSettings = new Button { Text = "Einstellungen", Width = 100, Height = 30 };
+            _btnReset = new Button { Text = "Sync Reset", Width = 80, Height = 30 };
+            _btnReset.Click += (s, e) => ResetSync();
+
+            _btnSettings = new Button { Text = "Einstellungen", Width = 95, 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, _btnSettings, _btnInfo });
+            buttonPanel.Controls.AddRange(new Control[] { _btnNew, _btnEdit, _btnDelete, _btnSync, _btnReset, _btnSettings, _btnInfo });
 
             // Statusbar
             _statusBar = new StatusStrip();
@@ -255,6 +258,36 @@ namespace StarfaceOutlookSync.UI
             }
         }
 
+        private void ResetSync()
+        {
+            if (_profileList.SelectedItems.Count == 0)
+            {
+                MessageBox.Show("Bitte ein Profil auswaehlen.", "Sync Reset",
+                    MessageBoxButtons.OK, MessageBoxIcon.Information);
+                return;
+            }
+
+            var profile = _profileList.SelectedItems[0].Tag as SyncProfile;
+            if (profile == null) return;
+
+            var msg = $"Sync-Zuordnungen fuer '{profile.Name}' zuruecksetzen?\n\n" +
+                      "Alle Kontakt-Verknuepfungen werden geloescht.\n" +
+                      "Beim naechsten Sync werden die Kontakte neu abgeglichen.\n" +
+                      "Es werden keine Kontakte geloescht.";
+
+            if (MessageBox.Show(msg, "Sync Reset",
+                MessageBoxButtons.YesNo, MessageBoxIcon.Warning) == DialogResult.Yes)
+            {
+                _profileManager.SaveMappings(profile.Id, new List<SyncMapping>());
+                // LastSync auch zuruecksetzen
+                profile.LastSync = "";
+                _profileManager.UpdateProfile(profile);
+                RefreshProfileList();
+                MessageBox.Show("Sync-Zuordnungen wurden zurueckgesetzt.",
+                    "Sync Reset", MessageBoxButtons.OK, MessageBoxIcon.Information);
+            }
+        }
+
         private Task SyncSelectedProfile()
         {
             if (_profileList.SelectedItems.Count == 0)