Enqueue support for Mailer

src/Admin/HostedServices/AzureQueueMailHostedService.cs

@@ -5,6 +5,7 @@
 using Azure.Storage.Queues;
 using Azure.Storage.Queues.Models;
 using Bit.Core.Models.Mail;
+using Bit.Core.Platform.Mail.Mailer;
 using Bit.Core.Services;
 using Bit.Core.Settings;
 using Bit.Core.Utilities;
@@ -16,6 +17,7 @@ public class AzureQueueMailHostedService : IHostedService
     private readonly ILogger<AzureQueueMailHostedService> _logger;
     private readonly GlobalSettings _globalSettings;
     private readonly IMailService _mailService;
+    private readonly IMailer _mailer;
     private CancellationTokenSource _cts;
     private Task _executingTask;
 
@@ -24,10 +26,12 @@ public class AzureQueueMailHostedService : IHostedService
     public AzureQueueMailHostedService(
         ILogger<AzureQueueMailHostedService> logger,
         IMailService mailService,
+        IMailer mailer,
         GlobalSettings globalSettings)
     {
         _logger = logger;
         _mailService = mailService;
+        _mailer = mailer;
         _globalSettings = globalSettings;
     }
 
@@ -72,13 +76,13 @@ private async Task ExecuteAsync(CancellationToken cancellationToken)
                     {
                         foreach (var mailQueueMessage in root.Deserialize<List<MailQueueMessage>>())
                         {
-                            await _mailService.SendEnqueuedMailMessageAsync(mailQueueMessage);
+                            await ProcessMailMessageAsync(mailQueueMessage);
                         }
                     }
                     else if (root.ValueKind == JsonValueKind.Object)
                     {
                         var mailQueueMessage = root.Deserialize<MailQueueMessage>();
-                        await _mailService.SendEnqueuedMailMessageAsync(mailQueueMessage);
+                        await ProcessMailMessageAsync(mailQueueMessage);
                     }
                 }
                 catch (Exception e)
@@ -101,4 +105,21 @@ private async Task<QueueMessage[]> RetrieveMessagesAsync()
     {
         return (await _mailQueueClient.ReceiveMessagesAsync(maxMessages: 32))?.Value ?? new QueueMessage[] { };
     }
+
+    /// <summary>
+    /// Processes a single mail message, checking if it's an IMailer message or HandlebarsMailService message.
+    /// </summary>
+    private async Task ProcessMailMessageAsync(MailQueueMessage message)
+    {
+        if (message.IsMailerMessage)
+        {
+            // IMailer message - delegate to mailer to render view and send
+            await _mailer.SendEnqueuedMailerMessageAsync(message);
+        }
+        else
+        {
+            // Template-based message from HandlebarsMailService
+            await _mailService.SendEnqueuedMailMessageAsync(message);
+        }
+    }
 }

src/Core/Models/Mail/IMailQueueMessage.cs

@@ -8,4 +8,14 @@ public interface IMailQueueMessage
     string Category { get; set; }
     string TemplateName { get; set; }
     object Model { get; set; }
+
+    /// <summary>
+    /// Indicates if this is an IMailer message (uses view rendering) vs HandlebarsMailService message (uses template rendering).
+    /// </summary>
+    public bool IsMailerMessage { get; set; }
+
+    /// <summary>
+    /// Additional metadata for delivery (e.g., SendGridBypassListManagement).
+    /// </summary>
+    public IDictionary<string, object>? MetaData { get; set; }
 }

src/Core/Models/Mail/MailQueueMessage.cs

@@ -17,6 +17,18 @@ public class MailQueueMessage : IMailQueueMessage
     [JsonConverter(typeof(HandlebarsObjectJsonConverter))]
     public object Model { get; set; }
 
+    /// <summary>
+    /// Indicates if this is an IMailer message (uses view rendering) vs HandlebarsMailService message (uses template rendering).
+    /// True for IMailer messages, false or null for HandlebarsMailService messages.
+    /// </summary>
+    public bool IsMailerMessage { get; set; }
+
+    /// <summary>
+    /// Additional metadata for delivery (e.g., SendGridBypassListManagement).
+    /// Used by both IMailer and HandlebarsMailService messages.
+    /// </summary>
+    public IDictionary<string, object> MetaData { get; set; }
+
     public MailQueueMessage() { }
 
     public MailQueueMessage(MailMessage message, string templateName, object model)

src/Core/Platform/Mail/Mailer/IMailer.cs

@@ -1,4 +1,6 @@
-namespace Bit.Core.Platform.Mail.Mailer;
+using Bit.Core.Models.Mail;
+
+namespace Bit.Core.Platform.Mail.Mailer;
 
 #nullable enable
 
@@ -12,4 +14,17 @@ public interface IMailer
     /// </summary>
     /// <param name="message"></param>
     public Task SendEmail<T>(BaseMail<T> message) where T : BaseMailView;
+
+    /// <summary>
+    /// Enqueues email messages for asynchronous delivery.
+    /// </summary>
+    /// <param name="messages">The email messages to enqueue</param>
+    /// <typeparam name="T">The type of the mail view</typeparam>
+    public Task EnqueueEmailsAsync<T>(IEnumerable<BaseMail<T>> messages) where T : BaseMailView;
+
+    /// <summary>
+    /// Sends a previously enqueued IMailer message by rendering the stored view and sending.
+    /// </summary>
+    /// <param name="queueMessage">The enqueued message containing view data</param>
+    public Task SendEnqueuedMailerMessageAsync(IMailQueueMessage queueMessage);
 }

src/Core/Platform/Mail/Mailer/Mailer.cs

@@ -1,32 +1,93 @@
 using Bit.Core.Models.Mail;
 using Bit.Core.Platform.Mail.Delivery;
+using Bit.Core.Platform.Mail.Enqueuing;
 
 namespace Bit.Core.Platform.Mail.Mailer;
 
-#nullable enable
-
-public class Mailer(IMailRenderer renderer, IMailDeliveryService mailDeliveryService) : IMailer
+public class Mailer(
+    IMailRenderer renderer,
+    IMailDeliveryService mailDeliveryService,
+    IMailEnqueuingService mailEnqueuingService) : IMailer
 {
     public async Task SendEmail<T>(BaseMail<T> message) where T : BaseMailView
     {
         var content = await renderer.RenderAsync(message.View);
 
-        var metadata = new Dictionary<string, object>();
-        if (message.IgnoreSuppressList)
-        {
-            metadata.Add("SendGridBypassListManagement", true);
-        }
-
         var mailMessage = new MailMessage
         {
             ToEmails = message.ToEmails,
             Subject = message.Subject,
-            MetaData = metadata,
+            MetaData = BuildMailMetadata(message.IgnoreSuppressList),
             HtmlContent = content.html,
             TextContent = content.txt,
             Category = message.Category,
         };
 
         await mailDeliveryService.SendEmailAsync(mailMessage);
     }
+
+    public async Task EnqueueEmailsAsync<T>(IEnumerable<BaseMail<T>> messages) where T : BaseMailView
+    {
+        var queueMessages = messages.Select(message => new MailQueueMessage
+        {
+            Subject = message.Subject,
+            ToEmails = message.ToEmails,
+            Category = message.Category ?? "Default",
+            TemplateName = typeof(T).AssemblyQualifiedName ?? throw new InvalidOperationException(),
+            Model = message.View,
+            IsMailerMessage = true,
+            MetaData = BuildMailMetadata(message.IgnoreSuppressList)
+        })
+            .ToList();
+
+        await mailEnqueuingService.EnqueueManyAsync(queueMessages, SendEnqueuedMailerMessageAsync);
+    }
+
+    /// <summary>
+    /// Sends a previously enqueued IMailer message by rendering the stored view and sending.
+    /// </summary>
+    public async Task SendEnqueuedMailerMessageAsync(IMailQueueMessage mailQueueMessage)
+    {
+        if (!mailQueueMessage.IsMailerMessage)
+        {
+            throw new InvalidOperationException(
+                "Expected IMailer message (IsMailerMessage = true)");
+        }
+
+        var viewType = Type.GetType(mailQueueMessage.TemplateName);
+        if (viewType == null)
+        {
+            throw new InvalidOperationException(
+                $"Could not resolve view type: {mailQueueMessage.TemplateName}");
+        }
+
+        if (mailQueueMessage.Model is not BaseMailView view)
+        {
+            throw new InvalidOperationException(
+                $"Model is not a BaseMailView: {mailQueueMessage.Model.GetType().FullName}");
+        }
+
+        var content = await renderer.RenderAsync(view);
+
+        var mailMessage = new MailMessage
+        {
+            ToEmails = mailQueueMessage.ToEmails,
+            Subject = mailQueueMessage.Subject,
+            BccEmails = mailQueueMessage.BccEmails,
+            Category = mailQueueMessage.Category,
+            MetaData = mailQueueMessage.MetaData ?? new Dictionary<string, object>(),
+            HtmlContent = content.html,
+            TextContent = content.txt
+        };
+
+        await mailDeliveryService.SendEmailAsync(mailMessage);
+    }
+
+    /// <summary>
+    /// Builds metadata dictionary for mail delivery based on mail settings.
+    /// </summary>
+    private static Dictionary<string, object> BuildMailMetadata(bool ignoreSuppressList) =>
+        ignoreSuppressList
+            ? new Dictionary<string, object> { { "SendGridBypassListManagement", true } }
+            : new Dictionary<string, object>();
 }

test/Core.Test/Auth/UserFeatures/EmergencyAccess/EmergencyAccessMailTests.cs

@@ -32,9 +32,11 @@ public async Task SendEmergencyAccessRemoveGranteesEmail_SingleGrantee_Success(
         var logger = Substitute.For<ILogger<HandlebarMailRenderer>>();
         var globalSettings = new GlobalSettings { SelfHosted = false };
         var deliveryService = Substitute.For<IMailDeliveryService>();
+        var enqueuingService = Substitute.For<Bit.Core.Platform.Mail.Enqueuing.IMailEnqueuingService>();
         var mailer = new Mailer(
             new HandlebarMailRenderer(logger, globalSettings),
-            deliveryService);
+            deliveryService,
+            enqueuingService);
 
         var mail = new EmergencyAccessRemoveGranteesMail
         {
@@ -73,9 +75,11 @@ public async Task SendEmergencyAccessRemoveGranteesEmail_MultipleGrantees_Render
         var logger = Substitute.For<ILogger<HandlebarMailRenderer>>();
         var globalSettings = new GlobalSettings { SelfHosted = false };
         var deliveryService = Substitute.For<IMailDeliveryService>();
+        var enqueuingService = Substitute.For<Bit.Core.Platform.Mail.Enqueuing.IMailEnqueuingService>();
         var mailer = new Mailer(
             new HandlebarMailRenderer(logger, globalSettings),
-            deliveryService);
+            deliveryService,
+            enqueuingService);
 
         var granteeEmails = new[] { "Alice@test.dev", "Bob@test.dev", "Carol@test.dev" };