diff --git a/Dashboard/MainWindow.xaml.cs b/Dashboard/MainWindow.xaml.cs
index 275917f..00027fb 100644
--- a/Dashboard/MainWindow.xaml.cs
+++ b/Dashboard/MainWindow.xaml.cs
@@ -60,7 +60,6 @@ public partial class MainWindow : Window
         private readonly ConcurrentDictionary<string, DateTime> _lastBlockingAlert = new();
         private readonly ConcurrentDictionary<string, DateTime> _lastDeadlockAlert = new();
         private readonly ConcurrentDictionary<string, DateTime> _lastHighCpuAlert = new();
-        private static readonly TimeSpan AlertCooldown = TimeSpan.FromMinutes(5);
         private readonly ConcurrentDictionary<string, bool> _activeBlockingAlert = new();
         private readonly ConcurrentDictionary<string, bool> _activeDeadlockAlert = new();
         private readonly ConcurrentDictionary<string, bool> _activeHighCpuAlert = new();
@@ -1097,6 +1096,7 @@ private async Task EvaluateAlertConditionsAsync(
             string serverId, string serverName, AlertHealthResult health, DatabaseService databaseService)
         {
             var prefs = _preferencesService.GetPreferences();
+            var alertCooldown = TimeSpan.FromMinutes(prefs.AlertCooldownMinutes);
 
             if (_alertStateService.IsAnySilencingActive(serverId))
             {
@@ -1112,7 +1112,7 @@ private async Task EvaluateAlertConditionsAsync(
             if (blockingExceeded)
             {
                 _activeBlockingAlert[serverId] = true;
-                if (!_lastBlockingAlert.TryGetValue(serverId, out var lastAlert) || (now - lastAlert) >= AlertCooldown)
+                if (!_lastBlockingAlert.TryGetValue(serverId, out var lastAlert) || (now - lastAlert) >= alertCooldown)
                 {
                     _notificationService?.ShowBlockingNotification(
                         serverName,
@@ -1158,7 +1158,7 @@ await _emailAlertService.TrySendAlertEmailAsync(
             if (deadlocksExceeded)
             {
                 _activeDeadlockAlert[serverId] = true;
-                if (!_lastDeadlockAlert.TryGetValue(serverId, out var lastAlert) || (now - lastAlert) >= AlertCooldown)
+                if (!_lastDeadlockAlert.TryGetValue(serverId, out var lastAlert) || (now - lastAlert) >= alertCooldown)
                 {
                     _notificationService?.ShowDeadlockNotification(
                         serverName,
@@ -1197,7 +1197,7 @@ await _emailAlertService.TrySendAlertEmailAsync(
             {
                 var totalCpu = health.TotalCpuPercent!.Value;
                 _activeHighCpuAlert[serverId] = true;
-                if (!_lastHighCpuAlert.TryGetValue(serverId, out var lastAlert) || (now - lastAlert) >= AlertCooldown)
+                if (!_lastHighCpuAlert.TryGetValue(serverId, out var lastAlert) || (now - lastAlert) >= alertCooldown)
                 {
                     _notificationService?.ShowHighCpuNotification(
                         serverName,
@@ -1233,7 +1233,7 @@ await _emailAlertService.TrySendAlertEmailAsync(
             if (triggeredWaits.Count > 0)
             {
                 _activePoisonWaitAlert[serverId] = true;
-                if (!_lastPoisonWaitAlert.TryGetValue(serverId, out var lastAlert) || (now - lastAlert) >= AlertCooldown)
+                if (!_lastPoisonWaitAlert.TryGetValue(serverId, out var lastAlert) || (now - lastAlert) >= alertCooldown)
                 {
                     var worst = triggeredWaits[0];
                     _notificationService?.ShowPoisonWaitNotification(serverName, worst.WaitType, worst.AvgMsPerWait);
@@ -1270,7 +1270,7 @@ await _emailAlertService.TrySendAlertEmailAsync(
             if (longRunningTriggered)
             {
                 _activeLongRunningQueryAlert[serverId] = true;
-                if (!_lastLongRunningQueryAlert.TryGetValue(serverId, out var lastAlert) || (now - lastAlert) >= AlertCooldown)
+                if (!_lastLongRunningQueryAlert.TryGetValue(serverId, out var lastAlert) || (now - lastAlert) >= alertCooldown)
                 {
                     var worst = health.LongRunningQueries[0];
                     var elapsedMinutes = worst.ElapsedSeconds / 60;
@@ -1311,7 +1311,7 @@ await _emailAlertService.TrySendAlertEmailAsync(
             {
                 var tempDb = health.TempDbSpace!;
                 _activeTempDbSpaceAlert[serverId] = true;
-                if (!_lastTempDbSpaceAlert.TryGetValue(serverId, out var lastAlert) || (now - lastAlert) >= AlertCooldown)
+                if (!_lastTempDbSpaceAlert.TryGetValue(serverId, out var lastAlert) || (now - lastAlert) >= alertCooldown)
                 {
                     _notificationService?.ShowTempDbSpaceNotification(serverName, tempDb.UsedPercent);
                     _lastTempDbSpaceAlert[serverId] = now;
@@ -1350,7 +1350,7 @@ await _emailAlertService.TrySendAlertEmailAsync(
                 var worst = health.AnomalousJobs[0];
                 var jobKey = $"{serverId}:{worst.JobId}:{worst.StartTime:O}";
 
-                if (!_lastLongRunningJobAlert.TryGetValue(jobKey, out var lastAlert) || (now - lastAlert) >= AlertCooldown)
+                if (!_lastLongRunningJobAlert.TryGetValue(jobKey, out var lastAlert) || (now - lastAlert) >= alertCooldown)
                 {
                     var currentMinutes = worst.CurrentDurationSeconds / 60;
                     _notificationService?.ShowLongRunningJobNotification(
diff --git a/Dashboard/Models/UserPreferences.cs b/Dashboard/Models/UserPreferences.cs
index 17e3ecb..a28a56c 100644
--- a/Dashboard/Models/UserPreferences.cs
+++ b/Dashboard/Models/UserPreferences.cs
@@ -94,6 +94,19 @@ public class UserPreferences
         public int TempDbSpaceThresholdPercent { get; set; } = 80; // Alert when TempDB used > X%
         public bool NotifyOnLongRunningJobs { get; set; } = true;
         public int LongRunningJobMultiplier { get; set; } = 3; // Alert when job runs > Nx historical average
+        private int _alertCooldownMinutes = 5;
+        public int AlertCooldownMinutes
+        {
+            get => _alertCooldownMinutes;
+            set => _alertCooldownMinutes = Math.Clamp(value, 1, 120);
+        }
+
+        private int _emailCooldownMinutes = 15;
+        public int EmailCooldownMinutes
+        {
+            get => _emailCooldownMinutes;
+            set => _emailCooldownMinutes = Math.Clamp(value, 1, 120);
+        }
 
         // SMTP email alert settings
         public bool SmtpEnabled { get; set; } = false;
diff --git a/Dashboard/Services/EmailAlertService.cs b/Dashboard/Services/EmailAlertService.cs
index e35bde0..d17db94 100644
--- a/Dashboard/Services/EmailAlertService.cs
+++ b/Dashboard/Services/EmailAlertService.cs
@@ -33,7 +33,6 @@ public class EmailAlertService
 
         private readonly UserPreferencesService _preferencesService;
         private readonly ConcurrentDictionary<string, DateTime> _cooldowns = new();
-        private static readonly TimeSpan CooldownPeriod = TimeSpan.FromMinutes(15);
 
         /* Alert log — loaded from JSON on startup, saved on exit, new alerts added in-memory */
         private readonly List<AlertLogEntry> _alertLog = new();
@@ -90,14 +89,14 @@ public async Task TrySendAlertEmailAsync(
 
                 var cooldownKey = $"{serverId}:{metricName}";
                 if (_cooldowns.TryGetValue(cooldownKey, out var lastSent) &&
-                    DateTime.UtcNow - lastSent < CooldownPeriod)
+                    DateTime.UtcNow - lastSent < TimeSpan.FromMinutes(prefs.EmailCooldownMinutes))
                 {
                     return;
                 }
 
                 var subject = $"[SQL Monitor Alert] {metricName} on {serverName}";
                 var (htmlBody, plainTextBody) = EmailTemplateBuilder.BuildAlertEmail(
-                    metricName, serverName, currentValue, thresholdValue, context);
+                    metricName, serverName, currentValue, thresholdValue, prefs.EmailCooldownMinutes, context);
 
                 string? sendError = null;
                 bool sent = false;
diff --git a/Dashboard/Services/EmailTemplateBuilder.cs b/Dashboard/Services/EmailTemplateBuilder.cs
index b72fa13..8738743 100644
--- a/Dashboard/Services/EmailTemplateBuilder.cs
+++ b/Dashboard/Services/EmailTemplateBuilder.cs
@@ -27,6 +27,7 @@ public static (string HtmlBody, string PlainTextBody) BuildAlertEmail(
             string serverName,
             string currentValue,
             string thresholdValue,
+            int emailCooldownMinutes,
             AlertContext? context = null)
         {
             var utcNow = DateTime.UtcNow;
@@ -34,7 +35,7 @@ public static (string HtmlBody, string PlainTextBody) BuildAlertEmail(
             var (accentColor, badgeText) = GetSeverity(metricName);
 
             var html = BuildHtmlBody(metricName, serverName, currentValue,
-                thresholdValue, utcNow, localNow, accentColor, badgeText, context: context);
+                thresholdValue, utcNow, localNow, accentColor, badgeText, context: context, emailCooldownMinutes: emailCooldownMinutes);
 
             var plain = BuildPlainTextBody(metricName, serverName, currentValue,
                 thresholdValue, utcNow, localNow, context);
@@ -87,7 +88,8 @@ private static string BuildHtmlBody(
             string accentColor,
             string badgeText,
             bool isTest = false,
-            AlertContext? context = null)
+            AlertContext? context = null,
+            int emailCooldownMinutes = 15)
         {
             var sb = new StringBuilder(2048);
 
@@ -167,7 +169,7 @@ private static string BuildHtmlBody(
             sb.Append($"Sent by {WebUtility.HtmlEncode(EditionName)}");
             if (!isTest)
             {
-                sb.Append(" &middot; 15-minute cooldown between repeat alerts");
+                sb.Append($" &middot; {emailCooldownMinutes}-minute cooldown between repeat alerts");
             }
             sb.Append("</span>");
             sb.Append("</td></tr>");
diff --git a/Dashboard/SettingsWindow.xaml b/Dashboard/SettingsWindow.xaml
index 5930e73..1b5266a 100644
--- a/Dashboard/SettingsWindow.xaml
+++ b/Dashboard/SettingsWindow.xaml
@@ -267,6 +267,16 @@
                             </StackPanel>
                             <TextBlock x:Name="AlertPreviewText" FontSize="11" FontStyle="Italic" Foreground="Gray"
                                        TextWrapping="Wrap" Margin="0,12,0,0"/>
+                            <StackPanel Orientation="Horizontal" Margin="0,12,0,0">
+                                <TextBlock Text="Tray notification cooldown:" VerticalAlignment="Center" Margin="0,0,8,0"/>
+                                <TextBox x:Name="AlertCooldownTextBox" Width="50" TextAlignment="Center" VerticalAlignment="Center"/>
+                                <TextBlock Text="minutes" VerticalAlignment="Center" Margin="4,0,0,0"/>
+                            </StackPanel>
+                            <StackPanel Orientation="Horizontal" Margin="0,6,0,0">
+                                <TextBlock Text="Email alert cooldown:" VerticalAlignment="Center" Margin="0,0,8,0"/>
+                                <TextBox x:Name="EmailCooldownTextBox" Width="50" TextAlignment="Center" VerticalAlignment="Center"/>
+                                <TextBlock Text="minutes" VerticalAlignment="Center" Margin="4,0,0,0"/>
+                            </StackPanel>
                         </StackPanel>
                     </StackPanel>
                 </ScrollViewer>
diff --git a/Dashboard/SettingsWindow.xaml.cs b/Dashboard/SettingsWindow.xaml.cs
index 5a39551..07364a8 100644
--- a/Dashboard/SettingsWindow.xaml.cs
+++ b/Dashboard/SettingsWindow.xaml.cs
@@ -171,6 +171,8 @@ private void LoadSettings()
             TempDbSpaceThresholdTextBox.Text = prefs.TempDbSpaceThresholdPercent.ToString(CultureInfo.InvariantCulture);
             NotifyOnLongRunningJobsCheckBox.IsChecked = prefs.NotifyOnLongRunningJobs;
             LongRunningJobMultiplierTextBox.Text = prefs.LongRunningJobMultiplier.ToString(CultureInfo.InvariantCulture);
+            AlertCooldownTextBox.Text = prefs.AlertCooldownMinutes.ToString(CultureInfo.InvariantCulture);
+            EmailCooldownTextBox.Text = prefs.EmailCooldownMinutes.ToString(CultureInfo.InvariantCulture);
 
             UpdateNotificationCheckboxStates();
 
@@ -311,6 +313,8 @@ private void RestoreAlertDefaultsButton_Click(object sender, RoutedEventArgs e)
             LongRunningQueryThresholdTextBox.Text = "30";
             TempDbSpaceThresholdTextBox.Text = "80";
             LongRunningJobMultiplierTextBox.Text = "3";
+            AlertCooldownTextBox.Text = "5";
+            EmailCooldownTextBox.Text = "15";
             UpdateAlertPreviewText();
         }
 
@@ -612,13 +616,15 @@ private void OkButton_Click(object sender, RoutedEventArgs e)
             else if (prefs.NotifyOnLongRunningJobs)
                 validationErrors.Add("Job multiplier must be a positive number");
 
-            if (validationErrors.Count > 0)
-            {
-                MessageBox.Show(
-                    "Some alert thresholds have invalid values and were not changed:\n\n" +
-                    string.Join("\n", validationErrors),
-                    "Validation", MessageBoxButton.OK, MessageBoxImage.Warning);
-            }
+            if (int.TryParse(AlertCooldownTextBox.Text, out int alertCooldown) && alertCooldown >= 1 && alertCooldown <= 120)
+                prefs.AlertCooldownMinutes = alertCooldown;
+            else
+                validationErrors.Add("Tray notification cooldown must be between 1 and 120 minutes");
+
+            if (int.TryParse(EmailCooldownTextBox.Text, out int emailCooldown) && emailCooldown >= 1 && emailCooldown <= 120)
+                prefs.EmailCooldownMinutes = emailCooldown;
+            else
+                validationErrors.Add("Email alert cooldown must be between 1 and 120 minutes");
 
             // Save SMTP email settings
             prefs.SmtpEnabled = SmtpEnabledCheckBox.IsChecked == true;
@@ -627,6 +633,8 @@ private void OkButton_Click(object sender, RoutedEventArgs e)
             {
                 prefs.SmtpPort = smtpPort;
             }
+            else 
+                validationErrors.Add("Smtp Port failed validation - must be a valid TCP port number.");
             prefs.SmtpUseSsl = SmtpSslCheckBox.IsChecked == true;
             prefs.SmtpUsername = SmtpUsernameTextBox.Text?.Trim() ?? "";
             prefs.SmtpFromAddress = SmtpFromTextBox.Text?.Trim() ?? "";
@@ -643,12 +651,25 @@ private void OkButton_Click(object sender, RoutedEventArgs e)
             {
                 prefs.McpPort = mcpPort;
             }
+            else
+                validationErrors.Add("MCP port failed validation - must be a valid TCP port number.");
 
             _preferencesService.SavePreferences(prefs);
 
             _saved = true;
-            DialogResult = true;
-            Close();
+
+            if (validationErrors.Count > 0)
+            {
+                MessageBox.Show(
+                    "Some settings have invalid values and were not changed:\n\n" +
+                    string.Join("\n", validationErrors),
+                    "Validation", MessageBoxButton.OK, MessageBoxImage.Warning);
+            }
+            else
+            {
+                DialogResult = true;
+                Close();
+            }
         }
 
         private void CancelButton_Click(object sender, RoutedEventArgs e)
diff --git a/Lite/App.xaml.cs b/Lite/App.xaml.cs
index bf9c405..df0f02b 100644
--- a/Lite/App.xaml.cs
+++ b/Lite/App.xaml.cs
@@ -73,6 +73,8 @@ public partial class App : Application
     public static int AlertTempDbSpaceThresholdPercent { get; set; } = 80;
     public static bool AlertLongRunningJobEnabled { get; set; } = true;
     public static int AlertLongRunningJobMultiplier { get; set; } = 3;
+    public static int AlertCooldownMinutes { get; set; } = 5;  // Tray notification cooldown between repeated alerts
+    public static int EmailCooldownMinutes { get; set; } = 15; // Email cooldown between repeated alerts
 
     /* Connection settings */
     public static int ConnectionTimeoutSeconds { get; set; } = 5;
@@ -256,6 +258,8 @@ public static void LoadAlertSettings()
             if (root.TryGetProperty("alert_tempdb_space_threshold_percent", out v)) AlertTempDbSpaceThresholdPercent = v.GetInt32();
             if (root.TryGetProperty("alert_long_running_job_enabled", out v)) AlertLongRunningJobEnabled = v.GetBoolean();
             if (root.TryGetProperty("alert_long_running_job_multiplier", out v)) AlertLongRunningJobMultiplier = v.GetInt32();
+            if (root.TryGetProperty("alert_cooldown_minutes", out v)) AlertCooldownMinutes = (int)Math.Clamp(v.GetInt64(), 1, 120);
+            if (root.TryGetProperty("email_cooldown_minutes", out v)) EmailCooldownMinutes = (int)Math.Clamp(v.GetInt64(), 1, 120);
 
             /* Connection settings */
             if (root.TryGetProperty("connection_timeout_seconds", out v))
diff --git a/Lite/MainWindow.xaml.cs b/Lite/MainWindow.xaml.cs
index 7e16095..0de4cbc 100644
--- a/Lite/MainWindow.xaml.cs
+++ b/Lite/MainWindow.xaml.cs
@@ -43,7 +43,6 @@ public partial class MainWindow : Window
     private readonly Dictionary<string, DateTime> _lastLongRunningQueryAlert = new();
     private readonly Dictionary<string, DateTime> _lastTempDbSpaceAlert = new();
     private readonly Dictionary<string, DateTime> _lastLongRunningJobAlert = new();
-    private static readonly TimeSpan AlertCooldown = TimeSpan.FromMinutes(5);
     private readonly DispatcherTimer _statusTimer;
     private LocalDataService? _dataService;
     private McpHostService? _mcpService;
@@ -963,6 +962,7 @@ private async void CheckPerformanceAlerts(ServerSummaryItem summary)
 
         var key = summary.ServerId.ToString();
         var now = DateTime.UtcNow;
+        var alertCooldown = TimeSpan.FromMinutes(App.AlertCooldownMinutes);
 
         /* Skip popup/email alerts if user has acknowledged or silenced this server */
         bool suppressPopups = !_alertStateService.ShouldShowAlerts(key);
@@ -975,7 +975,7 @@ private async void CheckPerformanceAlerts(ServerSummaryItem summary)
         if (cpuExceeded)
         {
             _activeCpuAlert[key] = true;
-            if (!suppressPopups && (!_lastCpuAlert.TryGetValue(key, out var lastCpu) || now - lastCpu >= AlertCooldown))
+            if (!suppressPopups && (!_lastCpuAlert.TryGetValue(key, out var lastCpu) || now - lastCpu >= alertCooldown))
             {
                 _trayService.ShowNotification(
                     "High CPU",
@@ -1007,7 +1007,7 @@ await _emailAlertService.TrySendAlertEmailAsync(
         if (blockingExceeded)
         {
             _activeBlockingAlert[key] = true;
-            if (!suppressPopups && (!_lastBlockingAlert.TryGetValue(key, out var lastBlocking) || now - lastBlocking >= AlertCooldown))
+            if (!suppressPopups && (!_lastBlockingAlert.TryGetValue(key, out var lastBlocking) || now - lastBlocking >= alertCooldown))
             {
                 _trayService.ShowNotification(
                     "Blocking Detected",
@@ -1042,7 +1042,7 @@ await _emailAlertService.TrySendAlertEmailAsync(
         if (deadlocksExceeded)
         {
             _activeDeadlockAlert[key] = true;
-            if (!suppressPopups && (!_lastDeadlockAlert.TryGetValue(key, out var lastDeadlock) || now - lastDeadlock >= AlertCooldown))
+            if (!suppressPopups && (!_lastDeadlockAlert.TryGetValue(key, out var lastDeadlock) || now - lastDeadlock >= alertCooldown))
             {
                 _trayService.ShowNotification(
                     "Deadlocks Detected",
@@ -1081,7 +1081,7 @@ await _emailAlertService.TrySendAlertEmailAsync(
                 if (triggered.Count > 0)
                 {
                     _activePoisonWaitAlert[key] = true;
-                    if (!suppressPopups && (!_lastPoisonWaitAlert.TryGetValue(key, out var lastPoisonWait) || now - lastPoisonWait >= AlertCooldown))
+                    if (!suppressPopups && (!_lastPoisonWaitAlert.TryGetValue(key, out var lastPoisonWait) || now - lastPoisonWait >= alertCooldown))
                     {
                         var worst = triggered[0];
                         var allWaitNames = string.Join(", ", triggered.ConvertAll(w => $"{w.WaitType} ({w.AvgMsPerWait:F0}ms)"));
@@ -1127,7 +1127,7 @@ await _emailAlertService.TrySendAlertEmailAsync(
                 if (longRunning.Count > 0)
                 {
                     _activeLongRunningQueryAlert[key] = true;
-                    if (!suppressPopups && (!_lastLongRunningQueryAlert.TryGetValue(key, out var lastLrq) || now - lastLrq >= AlertCooldown))
+                    if (!suppressPopups && (!_lastLongRunningQueryAlert.TryGetValue(key, out var lastLrq) || now - lastLrq >= alertCooldown))
                     {
                         var worst = longRunning[0];
                         var elapsedMinutes = worst.ElapsedSeconds / 60;
@@ -1175,7 +1175,7 @@ await _emailAlertService.TrySendAlertEmailAsync(
                 if (tempDb != null && tempDb.UsedPercent >= App.AlertTempDbSpaceThresholdPercent)
                 {
                     _activeTempDbSpaceAlert[key] = true;
-                    if (!suppressPopups && (!_lastTempDbSpaceAlert.TryGetValue(key, out var lastTempDb) || now - lastTempDb >= AlertCooldown))
+                    if (!suppressPopups && (!_lastTempDbSpaceAlert.TryGetValue(key, out var lastTempDb) || now - lastTempDb >= alertCooldown))
                     {
                         _trayService.ShowNotification(
                             "TempDB Space",
@@ -1223,7 +1223,7 @@ await _emailAlertService.TrySendAlertEmailAsync(
                     var worst = anomalousJobs[0];
                     var jobKey = $"{key}:{worst.JobId}:{worst.StartTime:O}";
 
-                    if (!suppressPopups && (!_lastLongRunningJobAlert.TryGetValue(jobKey, out var lastJob) || now - lastJob >= AlertCooldown))
+                    if (!suppressPopups && (!_lastLongRunningJobAlert.TryGetValue(jobKey, out var lastJob) || now - lastJob >= alertCooldown))
                     {
                         var currentMinutes = worst.CurrentDurationSeconds / 60;
                         _trayService.ShowNotification(
diff --git a/Lite/Services/EmailAlertService.cs b/Lite/Services/EmailAlertService.cs
index f837221..bbb35ed 100644
--- a/Lite/Services/EmailAlertService.cs
+++ b/Lite/Services/EmailAlertService.cs
@@ -25,7 +25,6 @@ namespace PerformanceMonitorLite.Services;
 public class EmailAlertService
 {
     private readonly ConcurrentDictionary<string, DateTime> _cooldowns = new();
-    private static readonly TimeSpan CooldownPeriod = TimeSpan.FromMinutes(15);
     private readonly DuckDbInitializer? _duckDb;
 
     /* Failure tracking for louder logging */
@@ -64,7 +63,7 @@ public async Task TrySendAlertEmailAsync(
             {
                 var cooldownKey = $"{serverId}:{metricName}";
                 var withinCooldown = _cooldowns.TryGetValue(cooldownKey, out var lastSent) &&
-                    DateTime.UtcNow - lastSent < CooldownPeriod;
+                    DateTime.UtcNow - lastSent < TimeSpan.FromMinutes(App.EmailCooldownMinutes);
 
                 if (!withinCooldown)
                 {
@@ -72,7 +71,7 @@ public async Task TrySendAlertEmailAsync(
 
                     var subject = $"[SQL Monitor Alert] {metricName} on {serverName}";
                     var (htmlBody, plainTextBody) = EmailTemplateBuilder.BuildAlertEmail(
-                        metricName, serverName, currentValue, thresholdValue, context);
+                        metricName, serverName, currentValue, thresholdValue, App.EmailCooldownMinutes, context);
 
                     try
                     {
diff --git a/Lite/Services/EmailTemplateBuilder.cs b/Lite/Services/EmailTemplateBuilder.cs
index 478f72d..7dd5596 100644
--- a/Lite/Services/EmailTemplateBuilder.cs
+++ b/Lite/Services/EmailTemplateBuilder.cs
@@ -29,6 +29,7 @@ public static (string HtmlBody, string PlainTextBody) BuildAlertEmail(
         string serverName,
         string currentValue,
         string thresholdValue,
+        int emailCooldownMinutes,
         AlertContext? context = null)
     {
         var utcNow = DateTime.UtcNow;
@@ -36,7 +37,7 @@ public static (string HtmlBody, string PlainTextBody) BuildAlertEmail(
         var (accentColor, badgeText) = GetSeverity(metricName);
 
         var html = BuildHtmlBody(metricName, serverName, currentValue,
-            thresholdValue, utcNow, localNow, accentColor, badgeText, context: context);
+            thresholdValue, utcNow, localNow, accentColor, badgeText, context: context, emailCooldownMinutes: emailCooldownMinutes);
 
         var plain = BuildPlainTextBody(metricName, serverName, currentValue,
             thresholdValue, utcNow, localNow, context);
@@ -89,7 +90,8 @@ private static string BuildHtmlBody(
         string accentColor,
         string badgeText,
         bool isTest = false,
-        AlertContext? context = null)
+        AlertContext? context = null,
+        int emailCooldownMinutes = 15)
     {
         var sb = new StringBuilder(2048);
 
@@ -169,7 +171,7 @@ private static string BuildHtmlBody(
         sb.Append($"Sent by {WebUtility.HtmlEncode(EditionName)}");
         if (!isTest)
         {
-            sb.Append(" &middot; 15-minute cooldown between repeat alerts");
+            sb.Append($" &middot; {emailCooldownMinutes}-minute cooldown between repeat alerts");
         }
         sb.Append("</span>");
         sb.Append("</td></tr>");
diff --git a/Lite/Windows/SettingsWindow.xaml b/Lite/Windows/SettingsWindow.xaml
index 098555b..284b5c2 100644
--- a/Lite/Windows/SettingsWindow.xaml
+++ b/Lite/Windows/SettingsWindow.xaml
@@ -218,6 +218,20 @@
                     <TextBlock Text="x historical average" VerticalAlignment="Center" Margin="2,0,0,0"
                                Foreground="{DynamicResource ForegroundBrush}"/>
                 </StackPanel>
+                <StackPanel Orientation="Horizontal" Margin="20,10,0,0">
+                    <TextBlock Text="Tray notification cooldown:" VerticalAlignment="Center" Margin="0,0,8,0"
+                               Foreground="{DynamicResource ForegroundBrush}"/>
+                    <TextBox x:Name="AlertCooldownBox" Width="40" TextAlignment="Center" VerticalAlignment="Center"/>
+                    <TextBlock Text="minutes" VerticalAlignment="Center" Margin="4,0,0,0"
+                               Foreground="{DynamicResource ForegroundBrush}"/>
+                </StackPanel>
+                <StackPanel Orientation="Horizontal" Margin="20,6,0,0">
+                    <TextBlock Text="Email alert cooldown:" VerticalAlignment="Center" Margin="0,0,8,0"
+                               Foreground="{DynamicResource ForegroundBrush}"/>
+                    <TextBox x:Name="EmailCooldownBox" Width="40" TextAlignment="Center" VerticalAlignment="Center"/>
+                    <TextBlock Text="minutes" VerticalAlignment="Center" Margin="4,0,0,0"
+                               Foreground="{DynamicResource ForegroundBrush}"/>
+                </StackPanel>
                 <TextBlock x:Name="AlertPreviewText" FontSize="11" FontStyle="Italic"
                            Foreground="{DynamicResource ForegroundMutedBrush}" TextWrapping="Wrap" Margin="20,10,0,0"/>
             </StackPanel>
diff --git a/Lite/Windows/SettingsWindow.xaml.cs b/Lite/Windows/SettingsWindow.xaml.cs
index 350458a..5408d6b 100644
--- a/Lite/Windows/SettingsWindow.xaml.cs
+++ b/Lite/Windows/SettingsWindow.xaml.cs
@@ -111,24 +111,26 @@ private void PauseResumeButton_Click(object sender, RoutedEventArgs e)
     private void SaveButton_Click(object sender, RoutedEventArgs e)
     {
         _scheduleManager.SaveSchedules();
-        bool mcpChanged = SaveMcpSettings();
+        var (mcpChanged, mcpValid) = SaveMcpSettings();
         SaveDefaultTimeRange();
         SaveConnectionTimeout();
         SaveCsvSeparator();
         SaveColorTheme();
         SaveTimeDisplayMode();
-        SaveAlertSettings();
+        bool alertsValid = SaveAlertSettings();
         SaveSmtpSettings();
 
         _saved = true;
 
+        if (!alertsValid || !mcpValid) return;
+
         var message = mcpChanged
             ? "Settings saved. MCP changes take effect after restarting the application."
             : "Settings saved.";
         MessageBox.Show(message, "Settings", MessageBoxButton.OK, MessageBoxImage.Information);
     }
 
-    private bool SaveMcpSettings()
+    private (bool Changed, bool Valid) SaveMcpSettings()
     {
         var settingsPath = Path.Combine(App.ConfigDirectory, "settings.json");
 
@@ -152,20 +154,32 @@ private bool SaveMcpSettings()
 
             root["mcp_enabled"] = newEnabled;
 
+            bool portValid = true;
             if (newPort > 0 && newPort < 65536)
             {
                 root["mcp_port"] = newPort;
             }
+            else
+            {
+                portValid = false;
+            }
 
             var options = new JsonSerializerOptions { WriteIndented = true };
             File.WriteAllText(settingsPath, root.ToJsonString(options));
 
-            return oldEnabled != newEnabled || oldPort != newPort;
+            if (!portValid)
+            {
+                MessageBox.Show(
+                    "MCP port failed validation - must be a valid TCP port number.\nOther MCP settings were saved.",
+                    "Settings", MessageBoxButton.OK, MessageBoxImage.Warning);
+            }
+
+            return (oldEnabled != newEnabled || oldPort != newPort, portValid);
         }
         catch (Exception ex)
         {
             AppLogger.Error("Settings", $"Failed to save MCP settings: {ex.Message}");
-            return false;
+            return (false, true);
         }
     }
 
@@ -445,10 +459,12 @@ private void LoadAlertSettings()
         AlertTempDbSpaceThresholdBox.Text = App.AlertTempDbSpaceThresholdPercent.ToString();
         AlertLongRunningJobCheckBox.IsChecked = App.AlertLongRunningJobEnabled;
         AlertLongRunningJobMultiplierBox.Text = App.AlertLongRunningJobMultiplier.ToString();
+        AlertCooldownBox.Text = App.AlertCooldownMinutes.ToString();
+        EmailCooldownBox.Text = App.EmailCooldownMinutes.ToString();
         UpdateAlertControlStates();
     }
 
-    private void SaveAlertSettings()
+    private bool SaveAlertSettings()
     {
         App.MinimizeToTray = MinimizeToTrayCheckBox.IsChecked == true;
         App.AlertsEnabled = AlertsEnabledCheckBox.IsChecked == true;
@@ -480,6 +496,15 @@ private void SaveAlertSettings()
         App.AlertLongRunningJobEnabled = AlertLongRunningJobCheckBox.IsChecked == true;
         if (int.TryParse(AlertLongRunningJobMultiplierBox.Text, out var jobMult) && jobMult >= 2 && jobMult <= 20)
             App.AlertLongRunningJobMultiplier = jobMult;
+        var validationErrors = new List<string>();
+        if (int.TryParse(AlertCooldownBox.Text, out var alertCooldown) && alertCooldown >= 1 && alertCooldown <= 120)
+            App.AlertCooldownMinutes = alertCooldown;
+        else
+            validationErrors.Add("Tray notification cooldown must be between 1 and 120 minutes.");
+        if (int.TryParse(EmailCooldownBox.Text, out var emailCooldown) && emailCooldown >= 1 && emailCooldown <= 120)
+            App.EmailCooldownMinutes = emailCooldown;
+        else
+            validationErrors.Add("Email alert cooldown must be between 1 and 120 minutes.");
 
         var settingsPath = Path.Combine(App.ConfigDirectory, "settings.json");
         try
@@ -517,6 +542,8 @@ private void SaveAlertSettings()
             root["alert_tempdb_space_threshold_percent"] = App.AlertTempDbSpaceThresholdPercent;
             root["alert_long_running_job_enabled"] = App.AlertLongRunningJobEnabled;
             root["alert_long_running_job_multiplier"] = App.AlertLongRunningJobMultiplier;
+            root["alert_cooldown_minutes"] = App.AlertCooldownMinutes;
+            root["email_cooldown_minutes"] = App.EmailCooldownMinutes;
 
             var options = new JsonSerializerOptions { WriteIndented = true };
             File.WriteAllText(settingsPath, root.ToJsonString(options));
@@ -525,6 +552,17 @@ private void SaveAlertSettings()
         {
             AppLogger.Error("Settings", $"Failed to save alert settings: {ex.Message}");
         }
+
+        if (validationErrors.Count > 0)
+        {
+            MessageBox.Show(
+                "Some alert settings have invalid values and were not changed:\n\n" +
+                string.Join("\n", validationErrors),
+                "Settings", MessageBoxButton.OK, MessageBoxImage.Warning);
+            return false;
+        }
+
+        return true;
     }
 
     private void AlertsEnabledCheckBox_Changed(object sender, RoutedEventArgs e)
@@ -541,6 +579,8 @@ private void RestoreAlertDefaultsButton_Click(object sender, RoutedEventArgs e)
         AlertLongRunningQueryThresholdBox.Text = "30";
         AlertTempDbSpaceThresholdBox.Text = "80";
         AlertLongRunningJobMultiplierBox.Text = "3";
+        AlertCooldownBox.Text = "5";
+        EmailCooldownBox.Text = "15";
         UpdateAlertPreviewText();
     }
 
diff --git a/README.md b/README.md
index fa8c4e3..94c163b 100644
--- a/README.md
+++ b/README.md
@@ -330,8 +330,10 @@ All thresholds are configurable in Settings.
 
 ### Notification Channels
 
-- **System tray** — balloon notifications with 5-minute per-metric cooldown
-- **Email (SMTP)** — styled HTML emails with 15-minute per-metric cooldown, configurable SMTP settings (server, port, SSL, authentication, recipients)
+- **System tray** — balloon notifications with a configurable per-metric cooldown (default: 5 minutes)
+- **Email (SMTP)** — styled HTML emails with a configurable per-metric cooldown (default: 15 minutes), plus configurable SMTP settings (server, port, SSL, authentication, recipients)
+
+Both cooldown periods are independently configurable in Settings under the Performance Alerts section.
 
 ### Email Alerts