diff --git a/Wino.Core.Domain/Interfaces/INotificationBuilder.cs b/Wino.Core.Domain/Interfaces/INotificationBuilder.cs
index 6b7fe872..aae5b2b2 100644
--- a/Wino.Core.Domain/Interfaces/INotificationBuilder.cs
+++ b/Wino.Core.Domain/Interfaces/INotificationBuilder.cs
@@ -31,6 +31,11 @@ public interface INotificationBuilder
     /// <param name="account">Account that needs attention.</param>
     void CreateAttentionRequiredNotification(MailAccount account);
 
+    /// <summary>
+    /// Shows a notification when WebView2 runtime is unavailable.
+    /// </summary>
+    void CreateWebView2RuntimeMissingNotification();
+
     /// <summary>
     /// Creates a calendar reminder toast for the specified calendar item.
     /// </summary>
diff --git a/Wino.Core.Domain/Interfaces/IWebView2RuntimeValidatorService.cs b/Wino.Core.Domain/Interfaces/IWebView2RuntimeValidatorService.cs
new file mode 100644
index 00000000..aafa0669
--- /dev/null
+++ b/Wino.Core.Domain/Interfaces/IWebView2RuntimeValidatorService.cs
@@ -0,0 +1,12 @@
+using System.Threading.Tasks;
+
+namespace Wino.Core.Domain.Interfaces;
+
+public interface IWebView2RuntimeValidatorService
+{
+    /// <summary>
+    /// Validates whether WebView2 runtime is installed and available for use.
+    /// </summary>
+    Task<bool> IsRuntimeAvailableAsync();
+}
+
diff --git a/Wino.Core.Domain/Translations/en_US/resources.json b/Wino.Core.Domain/Translations/en_US/resources.json
index ec1838e5..15012aa4 100644
--- a/Wino.Core.Domain/Translations/en_US/resources.json
+++ b/Wino.Core.Domain/Translations/en_US/resources.json
@@ -238,6 +238,8 @@
     "Error_FailedToSetupSystemFolders_Title": "Failed to setup system folders",
     "Exception_AccountNeedsAttention_Title": "Account needs attention",
     "Exception_AccountNeedsAttention_Message": "'{0}' requires your attention to continue working.",
+    "Exception_WebView2RuntimeMissing_Message": "Wino Mail could not find Microsoft Edge WebView2 Runtime. Please install or repair the runtime to render message content correctly.",
+    "Exception_WebView2RuntimeMissing_Title": "WebView2 runtime is required",
     "Exception_AuthenticationCanceled": "Authentication canceled",
     "Exception_CustomThemeExists": "This theme already exists.",
     "Exception_CustomThemeMissingName": "You must provide a name.",
diff --git a/Wino.Mail.ViewModels/MailAppShellViewModel.cs b/Wino.Mail.ViewModels/MailAppShellViewModel.cs
index 68d8226a..6482a979 100644
--- a/Wino.Mail.ViewModels/MailAppShellViewModel.cs
+++ b/Wino.Mail.ViewModels/MailAppShellViewModel.cs
@@ -77,6 +77,7 @@ public partial class MailAppShellViewModel : MailBaseViewModel,
     private readonly IWinoRequestDelegator _winoRequestDelegator;
     private readonly IMailDialogService _dialogService;
     private readonly IMimeFileService _mimeFileService;
+    private readonly IWebView2RuntimeValidatorService _webView2RuntimeValidatorService;
 
     private readonly INativeAppService _nativeAppService;
     private readonly IMailService _mailService;
@@ -98,7 +99,8 @@ public partial class MailAppShellViewModel : MailBaseViewModel,
                              IFolderService folderService,
                              IStatePersistanceService statePersistanceService,
                              IConfigurationService configurationService,
-                             IStartupBehaviorService startupBehaviorService)
+                             IStartupBehaviorService startupBehaviorService,
+                             IWebView2RuntimeValidatorService webView2RuntimeValidatorService)
     {
         StatePersistenceService = statePersistanceService;
 
@@ -118,6 +120,7 @@ public partial class MailAppShellViewModel : MailBaseViewModel,
         _launchProtocolService = launchProtocolService;
         _notificationBuilder = notificationBuilder;
         _winoRequestDelegator = winoRequestDelegator;
+        _webView2RuntimeValidatorService = webView2RuntimeValidatorService;
     }
 
     protected override void OnDispatcherAssigned()
@@ -233,6 +236,7 @@ public partial class MailAppShellViewModel : MailBaseViewModel,
 
         await RecreateMenuItemsAsync();
         await ProcessLaunchOptionsAsync();
+        await ValidateWebView2RuntimeAsync();
 
         if (!Debugger.IsAttached)
         {
@@ -242,6 +246,16 @@ public partial class MailAppShellViewModel : MailBaseViewModel,
         await MakeSureEnableStartupLaunchAsync();
     }
 
+    private async Task ValidateWebView2RuntimeAsync()
+    {
+        var isRuntimeAvailable = await _webView2RuntimeValidatorService.IsRuntimeAvailableAsync();
+
+        if (!isRuntimeAvailable)
+        {
+            await ExecuteUIThread(() => _notificationBuilder.CreateWebView2RuntimeMissingNotification());
+        }
+    }
+
     private async Task MakeSureEnableStartupLaunchAsync()
     {
         if (!_configurationService.Get<bool>(IsActivateStartupLaunchAskedKey, false))
diff --git a/Wino.Mail.WinUI/CoreUWPContainerSetup.cs b/Wino.Mail.WinUI/CoreUWPContainerSetup.cs
index fe804730..7c7ca562 100644
--- a/Wino.Mail.WinUI/CoreUWPContainerSetup.cs
+++ b/Wino.Mail.WinUI/CoreUWPContainerSetup.cs
@@ -29,6 +29,7 @@ public static class CoreUWPContainerSetup
         services.AddTransient<IFileService, FileService>();
         services.AddTransient<IStoreRatingService, StoreRatingService>();
         services.AddTransient<IKeyPressService, KeyPressService>();
+        services.AddTransient<IWebView2RuntimeValidatorService, WebView2RuntimeValidatorService>();
         services.AddTransient<INotificationBuilder, NotificationBuilder>();
         services.AddSingleton<ICalendarReminderServer, CalendarReminderServer>();
         services.AddTransient<IClipboardService, ClipboardService>();
diff --git a/Wino.Mail.WinUI/Services/NotificationBuilder.cs b/Wino.Mail.WinUI/Services/NotificationBuilder.cs
index dbf27526..c251a61e 100644
--- a/Wino.Mail.WinUI/Services/NotificationBuilder.cs
+++ b/Wino.Mail.WinUI/Services/NotificationBuilder.cs
@@ -252,6 +252,18 @@ public class NotificationBuilder : INotificationBuilder
         builder.Show();
     }
 
+    public void CreateWebView2RuntimeMissingNotification()
+    {
+        var builder = new ToastContentBuilder();
+        builder.SetToastScenario(ToastScenario.Default);
+
+        builder.AddText(Translator.Exception_WebView2RuntimeMissing_Title);
+        builder.AddText(Translator.Exception_WebView2RuntimeMissing_Message);
+
+        builder.AddButton(GetDismissButton());
+        builder.Show();
+    }
+
     public Task CreateCalendarReminderNotificationAsync(CalendarItem calendarItem, long reminderDurationInSeconds)
     {
         if (calendarItem == null)
diff --git a/Wino.Mail.WinUI/Services/WebView2RuntimeValidatorService.cs b/Wino.Mail.WinUI/Services/WebView2RuntimeValidatorService.cs
new file mode 100644
index 00000000..5b8fb458
--- /dev/null
+++ b/Wino.Mail.WinUI/Services/WebView2RuntimeValidatorService.cs
@@ -0,0 +1,26 @@
+using System;
+using System.Threading.Tasks;
+using Microsoft.Web.WebView2.Core;
+using Serilog;
+using Wino.Core.Domain.Interfaces;
+
+namespace Wino.Mail.WinUI.Services;
+
+public class WebView2RuntimeValidatorService : IWebView2RuntimeValidatorService
+{
+    public Task<bool> IsRuntimeAvailableAsync()
+    {
+        try
+        {
+            var version = CoreWebView2Environment.GetAvailableBrowserVersionString();
+            var hasRuntime = !string.IsNullOrWhiteSpace(version);
+
+            return Task.FromResult(hasRuntime);
+        }
+        catch (Exception ex)
+        {
+            Log.Error(ex, "WebView2 runtime validation failed.");
+            return Task.FromResult(false);
+        }
+    }
+}