diff --git a/src/infrastructure/DigitalData.MessagingService.Infrastructure/DependencyInjection.cs b/src/infrastructure/DigitalData.MessagingService.Infrastructure/DependencyInjection.cs
index 2a7ebf6..8b713f6 100644
--- a/src/infrastructure/DigitalData.MessagingService.Infrastructure/DependencyInjection.cs
+++ b/src/infrastructure/DigitalData.MessagingService.Infrastructure/DependencyInjection.cs
@@ -29,13 +29,17 @@ public static class DependencyInjection
         IConfiguration configuration)
     {
         // --- External Services ---
-        // Email Service - SMTP outbound (Limilabs Mail.dll)
-        services.AddSingleton<IEmailService, LimilabsEmailService>();
+        // Email Service - SMTP outbound (Limilabs Mail.dll) - OAuth2 aware
+        services.AddSingleton<IOAuth2TokenService, MicrosoftOAuth2TokenService>();
+        services.AddSingleton<LimilabsEmailService>();
+        services.AddSingleton<IEmailService>(sp => sp.GetRequiredService<LimilabsEmailService>());
 
         // Email Service - IMAP inbound (Limilabs Mail.dll)
-        // Fresh connection per call — stateless and thread-safe.
         services.AddScoped<IImapEmailService, LimilabsImapEmailService>();
-        
+
+        // Email Service - POP3 inbound (Limilabs Mail.dll)
+        services.AddScoped<IPop3EmailService, LimilabsPop3EmailService>();
+
         // PDF Processing Service (using DevExpress.Pdf)
         services.AddScoped<IPdfProcessingService, DevExpressPdfProcessingService>();
         
diff --git a/src/infrastructure/DigitalData.MessagingService.Infrastructure/Queue/SendingEmailConsumer.cs b/src/infrastructure/DigitalData.MessagingService.Infrastructure/Queue/SendingEmailConsumer.cs
index 80c6f0a..acf5102 100644
--- a/src/infrastructure/DigitalData.MessagingService.Infrastructure/Queue/SendingEmailConsumer.cs
+++ b/src/infrastructure/DigitalData.MessagingService.Infrastructure/Queue/SendingEmailConsumer.cs
@@ -2,6 +2,7 @@ using System.Text;
 using System.Text.Json;
 using DigitalData.MessagingService.Application.Common.Interfaces;
 using DigitalData.MessagingService.RabbitMQ;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using RabbitMQ.Client;
 using RabbitMQ.Client.Events;
@@ -31,7 +32,7 @@ public sealed class SendingEmailConsumer : IAsyncDisposable
     /// </summary>
     public Guid RuntimeId { get; } = Guid.NewGuid();
 
-    public SendingEmailConsumer(string queueName, IEmailService emailService, RabbitMqConnectionFactory cnnFactory, ILogger<SendingEmailConsumer>? logger = null)
+    public SendingEmailConsumer(string queueName, IEmailService emailService, IServiceScopeFactory scopeFactory, RabbitMqConnectionFactory cnnFactory, ILogger<SendingEmailConsumer>? logger = null)
     {
         _logger = logger;
         _queueName = queueName;
@@ -41,8 +42,6 @@ public sealed class SendingEmailConsumer : IAsyncDisposable
         {
             var channel = await _lazyChannel.Value;
 
-            // prefetchCount=1 ensures this consumer processes one message at a time before acking.
-            // Parallelism comes from running multiple consumer instances, not from within a single channel.
             await channel.BasicQosAsync(prefetchSize: 0, prefetchCount: 1, global: false);
 
             var consumer = new AsyncEventingBasicConsumer(channel);
@@ -57,8 +56,14 @@ public sealed class SendingEmailConsumer : IAsyncDisposable
 
                     if (oMailEvent is not null)
                     {
-                        // Send email via SMTP (SMTP config is injected in IEmailService via IOptions)
-                        await emailService.SendEmailAsync(oMailEvent.Mail, args.CancellationToken);
+                        if (oMailEvent.UseImapAppend)
+                        {
+                            await using var scope = scopeFactory.CreateAsyncScope();
+                            var imapService = scope.ServiceProvider.GetRequiredService<IImapEmailService>();
+                            await imapService.SendAndAppendAsync(oMailEvent.Mail, oMailEvent.SentFolder, args.CancellationToken);
+                        }
+                        else
+                            await emailService.SendEmailAsync(oMailEvent.Mail, args.CancellationToken);
 
                         // Acknowledge message after successful processing
                         await channel.BasicAckAsync(args.DeliveryTag, false, args.CancellationToken);
diff --git a/src/infrastructure/DigitalData.MessagingService.Infrastructure/Queue/SendingEmailConsumerPool.cs b/src/infrastructure/DigitalData.MessagingService.Infrastructure/Queue/SendingEmailConsumerPool.cs
index 691b62c..7242eec 100644
--- a/src/infrastructure/DigitalData.MessagingService.Infrastructure/Queue/SendingEmailConsumerPool.cs
+++ b/src/infrastructure/DigitalData.MessagingService.Infrastructure/Queue/SendingEmailConsumerPool.cs
@@ -1,5 +1,6 @@
 using DigitalData.MessagingService.Application.Common.Interfaces;
 using DigitalData.MessagingService.RabbitMQ;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 
@@ -8,8 +9,6 @@ namespace DigitalData.MessagingService.Infrastructure.Queue;
 /// <summary>
 /// Manages a pool of <see cref="SendingEmailConsumer"/> instances that compete for messages
 /// on the same RabbitMQ queue (competing consumers pattern).
-/// Each consumer owns a dedicated channel, so they process messages fully in parallel
-/// without any shared locking or synchronization primitives.
 /// </summary>
 public sealed class SendingEmailConsumerPool : IAsyncDisposable
 {
@@ -20,6 +19,7 @@ public sealed class SendingEmailConsumerPool : IAsyncDisposable
     public SendingEmailConsumerPool(
         IOptions<RabbitMqConfiguration> config,
         IEmailService emailService,
+        IServiceScopeFactory scopeFactory,
         RabbitMqConnectionFactory cnnFactory,
         ILogger<SendingEmailConsumerPool>? logger = null,
         ILogger<SendingEmailConsumer>? consumerLogger = null)
@@ -29,7 +29,7 @@ public sealed class SendingEmailConsumerPool : IAsyncDisposable
 
         _consumers = [.. Enumerable
             .Range(0, _concurrency)
-            .Select(_ => new SendingEmailConsumer(config.Value.QueueName, emailService, cnnFactory, consumerLogger))];
+            .Select(_ => new SendingEmailConsumer(config.Value.QueueName, emailService, scopeFactory, cnnFactory, consumerLogger))];
     }
 
     /// <summary>