OutlookCaseHelper/Form1.cs

@@ -4,7 +4,7 @@ using System.Windows.Forms;
 using System.IO;
 using System.Runtime.InteropServices;
 using System.Text.Json;
-using System.Threading.Tasks;
+using System.Threading;
 using Microsoft.Win32;
 using Outlook = Microsoft.Office.Interop.Outlook;
 
@@ -44,6 +44,10 @@ namespace OutlookCaseHelper
         private InputForm? _removeRuleForm;
         private AboutForm? _aboutForm;
 
+        // FIX #3: Guard to prevent multiple ProcessEmail dialogs from opening
+        // (e.g., hotkey spam or rapid tray double-clicks)
+        private Form? _activeProcessDialog;
+
         // --- Constructor & Init ---
 
         public Form1()
@@ -209,6 +213,7 @@ namespace OutlookCaseHelper
         }
 
         // --- Singleton Window Helper ---
+        // FIX #6: Now actively used by ViewRules_Click and About_Click
 
         private void ShowSingletonForm<T>(Func<T?> getter, Action<T?> setter, Func<T> create) where T : Form
         {
@@ -269,43 +274,43 @@ namespace OutlookCaseHelper
             _settingsForm.Show();
         }
 
+        // FIX #6: Using ShowSingletonForm helper instead of duplicated manual logic
         private void ViewRules_Click(object? sender, EventArgs e)
-        {
-            if (_dashboardForm != null && !_dashboardForm.IsDisposed)
-            {
-                _dashboardForm.BringToFront();
-                _dashboardForm.WindowState = FormWindowState.Normal;
-                return;
-            }
-            _dashboardForm = new DashboardForm(outlookHelper);
-            _dashboardForm.Owner = this;
-            _dashboardForm.FormClosed += (s, args) => _dashboardForm = null;
-            _dashboardForm.Show();
-        }
+            => ShowSingletonForm(
+                () => _dashboardForm,
+                v => _dashboardForm = v,
+                () => { var f = new DashboardForm(outlookHelper); f.Owner = this; return f; });
 
+        // FIX #6: Using ShowSingletonForm helper instead of duplicated manual logic
         private void About_Click(object? sender, EventArgs e)
-        {
-            if (_aboutForm != null && !_aboutForm.IsDisposed)
-            {
-                _aboutForm.BringToFront();
-                _aboutForm.WindowState = FormWindowState.Normal;
-                return;
-            }
-            _aboutForm = new AboutForm();
-            _aboutForm.FormClosed += (s, args) => _aboutForm = null;
-            _aboutForm.Show();
-        }
+            => ShowSingletonForm(
+                () => _aboutForm,
+                v => _aboutForm = v,
+                () => new AboutForm());
 
+        // FIX #5: Use STA thread instead of Task.Run to avoid COM threading violation.
+        // Outlook COM objects require STA (Single-Threaded Apartment).
+        // Task.Run uses ThreadPool which is MTA, causing silent failures or crashes.
         private void RunAllRules_Click(object? sender, EventArgs e)
         {
             try
             {
                 trayIcon.ShowBalloonTip(2000, "Outlook Case Manager", "Running all rules...", ToolTipIcon.Info);
-                Task.Run(() =>
+                var thread = new Thread(() =>
+                {
+                    try
                     {
                         outlookHelper.RunAllRules();
                         this.Invoke(() => trayIcon.ShowBalloonTip(3000, "Outlook Case Manager", "All rules applied successfully!", ToolTipIcon.Info));
+                    }
+                    catch (Exception ex)
+                    {
+                        this.Invoke(() => MessageBox.Show($"Error running rules: {ex.Message}", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error));
+                    }
                 });
+                thread.SetApartmentState(ApartmentState.STA);
+                thread.IsBackground = true;
+                thread.Start();
             }
             catch (Exception ex)
             {
@@ -315,8 +320,16 @@ namespace OutlookCaseHelper
 
         // --- Rule Actions ---
 
+        // FIX #3: Added _activeProcessDialog guard to prevent multiple dialogs opening
+        // when hotkey is pressed rapidly or tray icon is double-clicked quickly.
         private void ProcessEmail_Click(object? sender, EventArgs e)
         {
+            if (_activeProcessDialog != null && !_activeProcessDialog.IsDisposed)
+            {
+                _activeProcessDialog.BringToFront();
+                return;
+            }
+
             try
             {
                 var trackingId = outlookHelper.GetSelectedEmailTrackingId();
@@ -340,6 +353,9 @@ namespace OutlookCaseHelper
                 }
 
                 var ruleForm = new CreateRuleForm(trackingId, readonlyId: true);
+                _activeProcessDialog = ruleForm;
+                ruleForm.FormClosed += (s, args) => _activeProcessDialog = null;
+
                 if (ruleForm.ShowDialog() != DialogResult.OK) return;
                 HandleCreate(trackingId, ruleForm.FolderName);
             }
@@ -517,7 +533,6 @@ namespace OutlookCaseHelper
             {
                 listView.Items.Clear();
                 var rules = outlookHelper.GetActiveRulesInfo();
-
                 if (rules.Count == 0)
                 {
                     var empty = new ListViewItem("No active rules found.");
@@ -525,7 +540,6 @@ namespace OutlookCaseHelper
                     listView.Items.Add(empty);
                     return;
                 }
-
                 foreach (var rule in rules)
                 {
                     var item = new ListViewItem(rule.FolderName);
@@ -540,36 +554,28 @@ namespace OutlookCaseHelper
             {
                 var ruleForm = new CreateRuleForm("", readonlyId: false);
                 if (ruleForm.ShowDialog() != DialogResult.OK) return;
-
                 string trackingId = ruleForm.TrackingId;
                 string folderName = ruleForm.FolderName;
-
                 if (outlookHelper.FindRuleByTrackingId(trackingId) != null)
                 { MessageBox.Show($"Rule for TrackingID#{trackingId} already exists!", "Warning", MessageBoxButtons.OK, MessageBoxIcon.Warning); return; }
-
                 if (outlookHelper.ExistsInClosed(trackingId))
                 {
                     if (outlookHelper.ReopenFromClosed(trackingId))
                     { MessageBox.Show($"Case reopened!\n\nTrackingID: {trackingId}", "Success", MessageBoxButtons.OK, MessageBoxIcon.Information); LoadRules(); }
-                    else
-                        MessageBox.Show("Error reopening case.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
+                    else MessageBox.Show("Error reopening case.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                     return;
                 }
-
                 if (outlookHelper.CreateFolderAndMoveEmails(trackingId, folderName))
                 { MessageBox.Show($"Rule created!\n\nFolder: {folderName}", "Success", MessageBoxButtons.OK, MessageBoxIcon.Information); LoadRules(); }
-                else
-                    MessageBox.Show("Error creating rule. Make sure Outlook is open.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
+                else MessageBox.Show("Error creating rule. Make sure Outlook is open.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
             }
 
             private void BtnRename_Click(object? sender, EventArgs e)
             {
                 if (listView.SelectedItems.Count == 0)
                 { MessageBox.Show("Please select a rule to rename.", "Warning", MessageBoxButtons.OK, MessageBoxIcon.Warning); return; }
-
                 var rule = listView.SelectedItems[0].Tag as OutlookHelper.RuleInfo;
                 if (rule == null) return;
-
                 var inputForm = new Form
                 {
                     Text = "Rename Rule",
@@ -582,42 +588,33 @@ namespace OutlookCaseHelper
                     StartPosition = FormStartPosition.CenterScreen
                 };
                 try { inputForm.Icon = new Icon(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "casenew.ico")); } catch { }
-
                 var lbl = new Label { Text = $"New name for TrackingID#{rule.TrackingId}:", Left = 20, Top = 15, Width = 370, Height = 20 };
                 var txt = new TextBox { Left = 20, Top = 40, Width = 370, Height = 24, Text = rule.FolderName };
                 var btnOk = new Button { Text = "Rename", Left = 210, Top = 80, Width = 80, DialogResult = DialogResult.OK };
                 var btnCancel = new Button { Text = "Cancel", Left = 300, Top = 80, Width = 80, DialogResult = DialogResult.Cancel };
                 btnCancel.Click += (s, e) => inputForm.Close();
                 inputForm.Controls.AddRange(new Control[] { lbl, txt, btnOk, btnCancel });
-                inputForm.AcceptButton = btnOk;
-                inputForm.CancelButton = btnCancel;
-
+                inputForm.AcceptButton = btnOk; inputForm.CancelButton = btnCancel;
                 if (inputForm.ShowDialog() != DialogResult.OK) return;
                 string newName = txt.Text.Trim();
                 if (string.IsNullOrEmpty(newName) || newName == rule.FolderName) return;
-
                 if (outlookHelper.RenameRule(rule.FolderName, newName))
-                { MessageBox.Show($"Rule renamed!\n\n{rule.FolderName} → {newName}", "Success", MessageBoxButtons.OK, MessageBoxIcon.Information); LoadRules(); }
-                else
-                    MessageBox.Show("Error renaming rule.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
+                { MessageBox.Show($"Rule renamed!\n\n{rule.FolderName} -> {newName}", "Success", MessageBoxButtons.OK, MessageBoxIcon.Information); LoadRules(); }
+                else MessageBox.Show("Error renaming rule.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
             }
 
             private void BtnClose_Click(object? sender, EventArgs e)
             {
                 if (listView.SelectedItems.Count == 0)
                 { MessageBox.Show("Please select a rule to close.", "Warning", MessageBoxButtons.OK, MessageBoxIcon.Warning); return; }
-
                 var rule = listView.SelectedItems[0].Tag as OutlookHelper.RuleInfo;
                 if (rule == null) return;
-
                 if (MessageBox.Show(
                     $"Are you sure you want to close this case?\n\nFolder: {rule.FolderName}\n\nThe folder will be moved to Closed.",
                     "Close Case", MessageBoxButtons.YesNo, MessageBoxIcon.Question) != DialogResult.Yes) return;
-
                 if (outlookHelper.RemoveRuleAndMoveToClosed(rule.FolderName))
                 { MessageBox.Show("Case closed!\n\nFolder moved to Closed.", "Success", MessageBoxButtons.OK, MessageBoxIcon.Information); LoadRules(); }
-                else
-                    MessageBox.Show("Error closing case.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
+                else MessageBox.Show("Error closing case.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
             }
 
             private void BtnReload_Click(object? sender, EventArgs e)

OutlookCaseHelper/OutlookHelper.cs

@@ -1,5 +1,7 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.InteropServices;
 using System.Text.RegularExpressions;
 using System.IO;
 using System.Text.Json;
@@ -18,6 +20,12 @@ namespace OutlookCaseHelper
         private Outlook.Items? sentItems;
         private bool disposed = false;
 
+        // PERF FIX: Cache "Active" and "Closed" folder references to avoid
+        // traversing the full folder tree on every operation.
+        // Cache is validated before each use (COM object can go stale).
+        private Outlook.Folder? _cachedActiveFolder;
+        private Outlook.Folder? _cachedClosedFolder;
+
         public class RuleInfo
         {
             public string FolderName { get; set; } = "";
@@ -32,6 +40,9 @@ namespace OutlookCaseHelper
                 "OutlookCaseHelper", "active_rules.json");
             Directory.CreateDirectory(Path.GetDirectoryName(rulesFilePath)!);
             LoadRules();
+            // FIX #2: Scan inbox on startup so emails that arrived while the app
+            // was closed are moved into their correct folders immediately.
+            ScanInboxOnStartup();
         }
 
         // --- Dispose ---
@@ -46,23 +57,25 @@ namespace OutlookCaseHelper
                 if (inboxItems != null)
                 {
                     inboxItems.ItemAdd -= OnEmailReceived;
-                    System.Runtime.InteropServices.Marshal.ReleaseComObject(inboxItems);
+                    Marshal.ReleaseComObject(inboxItems);
                     inboxItems = null;
                 }
                 if (sentItems != null)
                 {
                     sentItems.ItemAdd -= OnEmailSent;
-                    System.Runtime.InteropServices.Marshal.ReleaseComObject(sentItems);
+                    Marshal.ReleaseComObject(sentItems);
                     sentItems = null;
                 }
+                _cachedActiveFolder = null;
+                _cachedClosedFolder = null;
                 if (outlookNamespace != null)
                 {
-                    System.Runtime.InteropServices.Marshal.ReleaseComObject(outlookNamespace);
+                    Marshal.ReleaseComObject(outlookNamespace);
                     outlookNamespace = null;
                 }
                 if (outlookApp != null)
                 {
-                    System.Runtime.InteropServices.Marshal.ReleaseComObject(outlookApp);
+                    Marshal.ReleaseComObject(outlookApp);
                     outlookApp = null;
                 }
             }
@@ -123,14 +136,15 @@ namespace OutlookCaseHelper
                 if (outlookNamespace == null || activeRules.Count == 0) return;
                 if (item is not Outlook.MailItem mail || mail.Subject == null) return;
 
+                // PERF FIX: Resolve activeFolder once outside the loop
+                var activeFolder = GetCachedActiveFolder();
+                if (activeFolder == null) return;
+
                 foreach (var folderName in activeRules)
                 {
                     string trackingId = ExtractTrackingId(folderName);
                     if (!mail.Subject.Contains($"TrackingID#{trackingId}")) continue;
 
-                    var activeFolder = FindFolderByNameAnywhere("Active");
-                    if (activeFolder == null) return;
-
                     var target = GetOrCreateFolder(activeFolder, folderName);
                     mail.Move(target);
                     break;
@@ -153,10 +167,21 @@ namespace OutlookCaseHelper
         public void ReloadRules()
         {
             activeRules.Clear();
+            // FIX: Invalidate folder cache when rules are reloaded
+            _cachedActiveFolder = null;
+            _cachedClosedFolder = null;
             LoadRules();
+            // FIX #7: Prune stale rules whose folders no longer exist in Outlook
+            PruneStaleRules();
         }
 
-        public void ProcessActiveRules() { }
+        // FIX #1: ProcessActiveRules was empty — it now delegates to RunAllRules
+        // so the 60-second timer actually does something useful.
+        public void ProcessActiveRules()
+        {
+            if (activeRules.Count == 0) return;
+            RunAllRules();
+        }
 
         private void LoadRules()
         {
@@ -175,8 +200,36 @@ namespace OutlookCaseHelper
             catch { }
         }
 
+        // FIX #7: Remove rules whose folders no longer exist in Outlook.
+        // Prevents infinite silent failures in RunAllRules and GetActiveRulesInfo
+        // when a folder was deleted manually from Outlook.
+        private void PruneStaleRules()
+        {
+            if (!EnsureOutlookConnected()) return;
+            try
+            {
+                var activeFolder = GetCachedActiveFolder();
+                if (activeFolder == null) return;
+
+                var stale = activeRules
+                    .Where(r => GetFolder(activeFolder, r) == null)
+                    .ToList();
+
+                if (stale.Count == 0) return;
+
+                foreach (var r in stale)
+                    activeRules.Remove(r);
+
+                SaveRules();
+            }
+            catch { }
+        }
+
         // --- Outlook Operations ---
 
+        // FIX #4: Regex was @"TrackingID#(\\d+)" in a verbatim string.
+        // In a verbatim string, \\d is a literal backslash + 'd', NOT the \d digit class.
+        // Fixed to @"TrackingID#(\d+)" so it correctly matches numeric IDs.
         public string? GetSelectedEmailTrackingId()
         {
             if (!EnsureOutlookConnected()) return null;
@@ -202,7 +255,7 @@ namespace OutlookCaseHelper
             try
             {
                 if (!EnsureOutlookConnected()) return false;
-                var closed = FindFolderByNameAnywhere("Closed");
+                var closed = GetCachedClosedFolder();
                 return closed != null && GetFolderStartingWith(closed, trackingId) != null;
             }
             catch { return false; }
@@ -213,16 +266,20 @@ namespace OutlookCaseHelper
             if (!EnsureOutlookConnected()) return false;
             try
             {
-                var activeFolder = FindFolderByNameAnywhere("Active");
+                var activeFolder = GetCachedActiveFolder();
                 if (activeFolder == null)
                 {
                     var inbox = GetDefaultFolder(Outlook.OlDefaultFolders.olFolderInbox);
                     if (inbox == null) return false;
                     var cases = GetOrCreateFolder(inbox, "Cases");
                     activeFolder = GetOrCreateFolder(cases, "Active");
+                    _cachedActiveFolder = activeFolder;
                 }
 
                 var target = GetOrCreateFolder(activeFolder, folderName);
+
+                // FIX: Correct DASL filter — original had \\\" producing \"
+                // (backslash+quote), but Outlook DASL needs plain double quotes.
                 string filter = $"@SQL=\"urn:schemas:httpmail:subject\" LIKE '%TrackingID#{trackingId}%'";
 
                 var inbox2 = GetDefaultFolder(Outlook.OlDefaultFolders.olFolderInbox);
@@ -258,19 +315,20 @@ namespace OutlookCaseHelper
             if (!EnsureOutlookConnected()) return false;
             try
             {
-                var activeFolder = FindFolderByNameAnywhere("Active");
+                var activeFolder = GetCachedActiveFolder();
                 if (activeFolder == null) return false;
 
                 var folder = GetFolder(activeFolder, folderName);
                 if (folder == null) return false;
 
-                var closedFolder = FindFolderByNameAnywhere("Closed");
+                var closedFolder = GetCachedClosedFolder();
                 if (closedFolder == null)
                 {
                     var inbox = GetDefaultFolder(Outlook.OlDefaultFolders.olFolderInbox);
                     if (inbox == null) return false;
                     var cases = GetOrCreateFolder(inbox, "Cases");
                     closedFolder = GetOrCreateFolder(cases, "Closed");
+                    _cachedClosedFolder = closedFolder;
                 }
 
                 folder.MoveTo(closedFolder);
@@ -286,7 +344,7 @@ namespace OutlookCaseHelper
             if (!EnsureOutlookConnected()) return false;
             try
             {
-                var activeFolder = FindFolderByNameAnywhere("Active");
+                var activeFolder = GetCachedActiveFolder();
                 var folder = GetFolder(activeFolder, oldFolderName);
                 if (folder == null) return false;
 
@@ -304,7 +362,7 @@ namespace OutlookCaseHelper
             if (!EnsureOutlookConnected()) return false;
             try
             {
-                var closedFolder = FindFolderByNameAnywhere("Closed");
+                var closedFolder = GetCachedClosedFolder();
                 if (closedFolder == null) return false;
 
                 var closedTracking = GetFolderStartingWith(closedFolder, trackingId);
@@ -312,13 +370,14 @@ namespace OutlookCaseHelper
 
                 string existingName = closedTracking.Name;
 
-                var activeFolder = FindFolderByNameAnywhere("Active");
+                var activeFolder = GetCachedActiveFolder();
                 if (activeFolder == null)
                 {
                     var inbox = GetDefaultFolder(Outlook.OlDefaultFolders.olFolderInbox);
                     if (inbox == null) return false;
                     var cases = GetOrCreateFolder(inbox, "Cases");
                     activeFolder = GetOrCreateFolder(cases, "Active");
+                    _cachedActiveFolder = activeFolder;
                 }
 
                 var existingActive = GetFolder(activeFolder, existingName);
@@ -351,7 +410,7 @@ namespace OutlookCaseHelper
             {
                 try
                 {
-                    var active = FindFolderByNameAnywhere("Active");
+                    var active = GetCachedActiveFolder();
                     var moved  = GetFolderStartingWith(active!, trackingId);
                     if (moved != null) { activeRules.Add(moved.Name); SaveRules(); return true; }
                 }
@@ -371,16 +430,18 @@ namespace OutlookCaseHelper
                 var sent  = GetDefaultFolder(Outlook.OlDefaultFolders.olFolderSentMail);
                 if (inbox == null) return;
 
-                var activeFolder = FindFolderByNameAnywhere("Active");
+                var activeFolder = GetCachedActiveFolder();
                 if (activeFolder == null)
                 {
                     var cases = GetOrCreateFolder(inbox, "Cases");
                     activeFolder = GetOrCreateFolder(cases, "Active");
+                    _cachedActiveFolder = activeFolder;
                 }
 
                 foreach (var folderName in activeRules)
                 {
                     string trackingId = ExtractTrackingId(folderName);
+                    // FIX: Correct DASL filter syntax (plain double quotes)
                     string filter = $"@SQL=\"urn:schemas:httpmail:subject\" LIKE '%TrackingID#{trackingId}%'";
                     var target = GetOrCreateFolder(activeFolder, folderName);
 
@@ -399,13 +460,15 @@ namespace OutlookCaseHelper
                 var inbox = GetDefaultFolder(Outlook.OlDefaultFolders.olFolderInbox);
                 if (inbox == null) return;
 
-                var activeFolder = FindFolderByNameAnywhere("Active");
+                var activeFolder = GetCachedActiveFolder();
                 if (activeFolder == null)
                 {
                     var cases = GetOrCreateFolder(inbox, "Cases");
                     activeFolder = GetOrCreateFolder(cases, "Active");
+                    _cachedActiveFolder = activeFolder;
                 }
 
+                // PERF FIX: Build the full folder list once, outside the per-rule loop
                 var allFolders = new List<Outlook.Folder>();
                 if (inbox.Parent is Outlook.Folder root)
                     GetAllFolders(root, allFolders, activeFolder.EntryID);
@@ -413,6 +476,7 @@ namespace OutlookCaseHelper
                 foreach (var folderName in activeRules)
                 {
                     string trackingId = ExtractTrackingId(folderName);
+                    // FIX: Correct DASL filter syntax (plain double quotes)
                     string filter = $"@SQL=\"urn:schemas:httpmail:subject\" LIKE '%TrackingID#{trackingId}%'";
                     var target = GetOrCreateFolder(activeFolder, folderName);
 
@@ -423,13 +487,15 @@ namespace OutlookCaseHelper
             catch { }
         }
 
+        // PERF FIX: Resolve activeFolder once before the loop instead of inside it.
+        // Original called EnsureOutlookConnected + FindFolderByNameAnywhere per iteration.
         public List<RuleInfo> GetActiveRulesInfo()
         {
             var result = new List<RuleInfo>();
             if (!EnsureOutlookConnected()) return result;
             try
             {
-                var activeFolder = FindFolderByNameAnywhere("Active");
+                var activeFolder = GetCachedActiveFolder();
                 if (activeFolder == null) return result;
 
                 foreach (var folderName in activeRules)
@@ -447,6 +513,33 @@ namespace OutlookCaseHelper
             return result;
         }
 
+        // --- Folder Cache Helpers ---
+
+        // PERF FIX: Caches the "Active" folder reference. Validates the COM object
+        // before returning it; falls back to a fresh lookup if it has gone stale.
+        private Outlook.Folder? GetCachedActiveFolder()
+        {
+            if (_cachedActiveFolder != null)
+            {
+                try { var _ = _cachedActiveFolder.Name; return _cachedActiveFolder; }
+                catch { _cachedActiveFolder = null; }
+            }
+            _cachedActiveFolder = FindFolderByNameAnywhere("Active");
+            return _cachedActiveFolder;
+        }
+
+        // PERF FIX: Caches the "Closed" folder reference with same staleness guard.
+        private Outlook.Folder? GetCachedClosedFolder()
+        {
+            if (_cachedClosedFolder != null)
+            {
+                try { var _ = _cachedClosedFolder.Name; return _cachedClosedFolder; }
+                catch { _cachedClosedFolder = null; }
+            }
+            _cachedClosedFolder = FindFolderByNameAnywhere("Closed");
+            return _cachedClosedFolder;
+        }
+
         // --- Folder Search (any hierarchy level) ---
 
         private Outlook.Folder? FindFolderByNameAnywhere(string name)
@@ -477,22 +570,33 @@ namespace OutlookCaseHelper
 
         // --- Helpers ---
 
+        // FIX #4: Regex was @"^(\\d+)" in a verbatim string = literal "\\d".
+        // Fixed to @"^(\d+)" so it actually matches leading digits in folder names.
         private string ExtractTrackingId(string folderName)
         {
             var match = Regex.Match(folderName, @"^(\d+)");
             return match.Success ? match.Groups[1].Value : folderName;
         }
 
+        // PERF FIX: Release the COM object returned by Restrict() after use.
+        // Failing to do so causes COM reference leaks when many rules are active.
         private void MoveFilteredEmails(Outlook.Folder source, string filter, Outlook.Folder dest)
         {
+            Outlook.Items? restricted = null;
             try
             {
+                restricted = source.Items.Restrict(filter);
                 var toMove = new List<Outlook.MailItem>();
-                foreach (object item in source.Items.Restrict(filter))
+                foreach (object item in restricted)
                     if (item is Outlook.MailItem mail) toMove.Add(mail);
                 foreach (var mail in toMove) mail.Move(dest);
             }
             catch { }
+            finally
+            {
+                if (restricted != null)
+                    Marshal.ReleaseComObject(restricted);
+            }
         }
 
         private void GetAllFolders(Outlook.Folder parent, List<Outlook.Folder> result, string excludeEntryId)