diff --git a/MessagingService.BusinessLogic.Tests/MessagingService.BusinessLogic.Tests.csproj b/MessagingService.BusinessLogic.Tests/MessagingService.BusinessLogic.Tests.csproj
index 6848542..73d33dc 100644
--- a/MessagingService.BusinessLogic.Tests/MessagingService.BusinessLogic.Tests.csproj
+++ b/MessagingService.BusinessLogic.Tests/MessagingService.BusinessLogic.Tests.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
 	  <TargetFramework>net8.0</TargetFramework>
-    <DebugType>None</DebugType>
+    <DebugType>Full</DebugType>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
diff --git a/MessagingService.BusinessLogic.Tests/Services/MessagingDomainServiceTests.cs b/MessagingService.BusinessLogic.Tests/Services/MessagingDomainServiceTests.cs
index eb5a999..7187ec3 100644
--- a/MessagingService.BusinessLogic.Tests/Services/MessagingDomainServiceTests.cs
+++ b/MessagingService.BusinessLogic.Tests/Services/MessagingDomainServiceTests.cs
@@ -57,6 +57,41 @@ public async Task MessagingDomainService_SendEmailMessage_MessageSent()
             result.Data.ShouldBe(TestData.MessageId);
         }
 
+        [Fact]
+        public async Task MessagingDomainService_SendEmailMessage_SecondSend_MessageNotSent()
+        {
+            Mock<IAggregateRepository<EmailAggregate, DomainEvent>> emailAggregateRepository = new Mock<IAggregateRepository<EmailAggregate, DomainEvent>>();
+            emailAggregateRepository.Setup(a => a.GetLatestVersion(It.IsAny<Guid>(), It.IsAny<CancellationToken>())).ReturnsAsync(TestData.GetSentEmailAggregate());
+            emailAggregateRepository.Setup(a => a.SaveChanges(It.IsAny<EmailAggregate>(), It.IsAny<CancellationToken>())).ReturnsAsync(Result.Success);
+            Mock<IAggregateRepository<SMSAggregate, DomainEvent>> smsAggregateRepository = new Mock<IAggregateRepository<SMSAggregate, DomainEvent>>();
+            Mock<IEmailServiceProxy> emailServiceProxy = new Mock<IEmailServiceProxy>();
+            emailServiceProxy
+                .Setup(e => e.SendEmail(It.IsAny<Guid>(),
+                                        It.IsAny<String>(),
+                                        It.IsAny<List<String>>(),
+                                        It.IsAny<String>(),
+                                        It.IsAny<String>(),
+                                        It.IsAny<Boolean>(),
+                                        It.IsAny<List<EmailAttachment>>(),
+                                        It.IsAny<CancellationToken>())).ReturnsAsync(TestData.SuccessfulEmailServiceProxyResponse);
+            Mock<ISMSServiceProxy> smsServiceProxy = new Mock<ISMSServiceProxy>();
+
+            MessagingDomainService messagingDomainService =
+                new MessagingDomainService(emailAggregateRepository.Object, smsAggregateRepository.Object, emailServiceProxy.Object, smsServiceProxy.Object);
+
+            var result = await messagingDomainService.SendEmailMessage(TestData.ConnectionIdentifier,
+                TestData.MessageId,
+                TestData.FromAddress,
+                TestData.ToAddresses,
+                TestData.Subject,
+                TestData.Body,
+                TestData.IsHtmlTrue,
+                TestData.EmailAttachmentModels,
+                CancellationToken.None);
+            result.IsSuccess.ShouldBeTrue();
+            result.Data.ShouldBe(TestData.MessageId);
+        }
+
         [Fact] public async Task MessagingDomainService_SendEmailMessage_SaveFailed_MessageSent()
         {
             Mock<IAggregateRepository<EmailAggregate, DomainEvent>> emailAggregateRepository = new Mock<IAggregateRepository<EmailAggregate, DomainEvent>>();
@@ -260,6 +295,35 @@ public async Task MessagingDomainService_SendSMSMessage_MessageSent()
 
         }
 
+        [Fact]
+        public async Task MessagingDomainService_SendSMSMessage_SecondTime_MessageNotSent()
+        {
+            Mock<IAggregateRepository<EmailAggregate, DomainEvent>> emailAggregateRepository = new Mock<IAggregateRepository<EmailAggregate, DomainEvent>>();
+            Mock<IAggregateRepository<SMSAggregate, DomainEvent>> smsAggregateRepository = new Mock<IAggregateRepository<SMSAggregate, DomainEvent>>();
+            smsAggregateRepository.Setup(a => a.GetLatestVersion(It.IsAny<Guid>(), It.IsAny<CancellationToken>())).ReturnsAsync(TestData.GetSentSMSAggregate());
+            smsAggregateRepository.Setup(a => a.SaveChanges(It.IsAny<SMSAggregate>(), It.IsAny<CancellationToken>())).ReturnsAsync(Result.Success());
+            Mock<IEmailServiceProxy> emailServiceProxy = new Mock<IEmailServiceProxy>();
+            Mock<ISMSServiceProxy> smsServiceProxy = new Mock<ISMSServiceProxy>();
+            smsServiceProxy
+                .Setup(e => e.SendSMS(It.IsAny<Guid>(),
+                    It.IsAny<String>(),
+                    It.IsAny<String>(),
+                    It.IsAny<String>(),
+                    It.IsAny<CancellationToken>())).ReturnsAsync(TestData.SuccessfulSMSServiceProxyResponse);
+            MessagingDomainService messagingDomainService =
+                new MessagingDomainService(emailAggregateRepository.Object, smsAggregateRepository.Object, emailServiceProxy.Object, smsServiceProxy.Object);
+
+            var result = await messagingDomainService.SendSMSMessage(TestData.ConnectionIdentifier,
+                TestData.MessageId,
+                TestData.Sender,
+                TestData.Destination,
+                TestData.Message,
+                CancellationToken.None);
+            result.IsSuccess.ShouldBeTrue(); 
+            result.Data.ShouldBe(TestData.MessageId);
+
+        }
+
         [Fact]
         public async Task MessagingDomainService_SendSMSMessage_SaveFailed_MessageSent()
         {
diff --git a/MessagingService.BusinessLogic/Services/MessagingDomainService.cs b/MessagingService.BusinessLogic/Services/MessagingDomainService.cs
index 2b56b8c..14b851f 100644
--- a/MessagingService.BusinessLogic/Services/MessagingDomainService.cs
+++ b/MessagingService.BusinessLogic/Services/MessagingDomainService.cs
@@ -120,8 +120,13 @@ public async Task<Result<Guid>> SendEmailMessage(Guid connectionIdentifier,
                                                          List<EmailAttachment> attachments,
                                                          CancellationToken cancellationToken) {
             Result result = await ApplyEmailUpdates(async (EmailAggregate emailAggregate) => {
+                // Check if this message has been sent before
+                if (emailAggregate.GetMessageStatus() != EmailMessageAggregate.MessageStatus.NotSet) {
+                    return Result.Success();
+                }
+
                 // send message to provider (record event)
-                emailAggregate.SendRequestToProvider(fromAddress, toAddresses, subject, body, isHtml, attachments);
+                    emailAggregate.SendRequestToProvider(fromAddress, toAddresses, subject, body, isHtml, attachments);
 
                 // Make call to Email provider here
                 EmailServiceProxyResponse emailResponse = await this.EmailServiceProxy.SendEmail(messageId, fromAddress,
@@ -152,6 +157,12 @@ public async Task<Result<Guid>> SendSMSMessage(Guid connectionIdentifier,
                                                        CancellationToken cancellationToken)
         {
             Result result = await ApplySMSUpdates(async (SMSAggregate smsAggregate) => {
+                // Check if this message has been sent before
+                if (smsAggregate.GetMessageStatus() != SMSMessageAggregate.MessageStatus.NotSet)
+                {
+                    return Result.Success();
+                }
+
                 // send message to provider (record event)
                 smsAggregate.SendRequestToProvider(sender, destination, message);
 
diff --git a/MessagingService.EmailAggregate.Tests/EmailAggregateTests.cs b/MessagingService.EmailAggregate.Tests/EmailAggregateTests.cs
index dcfb34a..9e9cfd6 100644
--- a/MessagingService.EmailAggregate.Tests/EmailAggregateTests.cs
+++ b/MessagingService.EmailAggregate.Tests/EmailAggregateTests.cs
@@ -44,21 +44,6 @@ public void EmailAggregate_SendRequestToProvider_RequestSent() {
             }
         }
 
-        [Fact]
-        public void EmailAggregate_SendRequestToProvider_RequestAlreadySent_NoErrorThrown() {
-            EmailAggregate emailAggregate = EmailAggregate.Create(TestData.MessageId);
-
-            emailAggregate.SendRequestToProvider(TestData.FromAddress, TestData.ToAddresses, TestData.Subject, TestData.Body, TestData.IsHtmlTrue, TestData.EmailAttachmentModels);
-
-            Should.NotThrow(() => {
-                                                        emailAggregate.SendRequestToProvider(TestData.FromAddress,
-                                                                                             TestData.ToAddresses,
-                                                                                             TestData.Subject,
-                                                                                             TestData.Body,
-                                                                                             TestData.IsHtmlTrue, TestData.EmailAttachmentModels);
-                                                    });
-        }
-
         [Fact]
         public void EmailAggregate_ReceiveResponseFromProvider_ResponseReceived() {
             EmailAggregate emailAggregate = EmailAggregate.Create(TestData.MessageId);
diff --git a/MessagingService.EmailMessageAggregate/EmailAggregate.cs b/MessagingService.EmailMessageAggregate/EmailAggregate.cs
index 2abf450..74eba7f 100644
--- a/MessagingService.EmailMessageAggregate/EmailAggregate.cs
+++ b/MessagingService.EmailMessageAggregate/EmailAggregate.cs
@@ -79,6 +79,11 @@ public static void ReceiveBadResponseFromProvider(this EmailAggregate aggregate,
             aggregate.ApplyAndAppend(badResponseReceivedFromProviderEvent);
         }
 
+        public static MessageStatus GetMessageStatus(this EmailAggregate aggregate)
+        {
+            return aggregate.DeliveryStatusList[aggregate.ResendCount];
+        }
+
         public static void SendRequestToProvider(this EmailAggregate aggregate, String fromAddress,
                                           List<String> toAddresses,
                                           String subject,
@@ -86,10 +91,6 @@ public static void SendRequestToProvider(this EmailAggregate aggregate, String f
                                           Boolean isHtml,
                                           List<EmailAttachment> attachments)
         {
-            if (aggregate.DeliveryStatusList[aggregate.ResendCount] != MessageStatus.NotSet) {
-                return;
-            }
-
             RequestSentToEmailProviderEvent requestSentToProviderEvent = new RequestSentToEmailProviderEvent(aggregate.AggregateId, fromAddress, toAddresses, subject, body, isHtml);
 
             aggregate.ApplyAndAppend(requestSentToProviderEvent);
diff --git a/MessagingService.SMSAggregate.Tests/SMSAggregateTests.cs b/MessagingService.SMSAggregate.Tests/SMSAggregateTests.cs
index dbb4984..af5b6c0 100644
--- a/MessagingService.SMSAggregate.Tests/SMSAggregateTests.cs
+++ b/MessagingService.SMSAggregate.Tests/SMSAggregateTests.cs
@@ -34,19 +34,6 @@ public void SMSAggregate_SendRequestToProvider_RequestSent()
             smsAggregate.GetDeliveryStatus().ShouldBe(MessageStatus.InProgress);
         }
 
-        [Fact]
-        public void SMSAggregate_SendRequestToProvider_RequestAlreadySent_NoErrorThrown()
-        {
-            SMSAggregate smsAggregate = SMSAggregate.Create(TestData.MessageId);
-
-            smsAggregate.SendRequestToProvider(TestData.Sender, TestData.Destination, TestData.Message);
-
-            Should.NotThrow(() =>
-            {
-                smsAggregate.SendRequestToProvider(TestData.Sender, TestData.Destination, TestData.Message);
-            });
-        }
-
         [Fact]
         public void SMSAggregate_ReceiveResponseFromProvider_ResponseReceived()
         {
diff --git a/MessagingService.SMSMessageAggregate/SMSAggregate.cs b/MessagingService.SMSMessageAggregate/SMSAggregate.cs
index 4c580ab..f23c715 100644
--- a/MessagingService.SMSMessageAggregate/SMSAggregate.cs
+++ b/MessagingService.SMSMessageAggregate/SMSAggregate.cs
@@ -113,9 +113,7 @@ public static void SendRequestToProvider(this SMSAggregate aggregate,
                                                  String sender,
                                                  String destination,
                                                  String message){
-            if (aggregate.DeliveryStatusList[aggregate.ResendCount] != MessageStatus.NotSet){
-                return;
-            }
+            
 
             RequestSentToSMSProviderEvent requestSentToProviderEvent = new RequestSentToSMSProviderEvent(aggregate.AggregateId, sender, destination, message);
 
@@ -146,6 +144,10 @@ private static void CheckMessageCanBeSetToUndeliverable(this SMSAggregate aggreg
             }
         }
 
+        public static MessageStatus GetMessageStatus(this SMSAggregate aggregate) {
+            return aggregate.DeliveryStatusList[aggregate.ResendCount];
+        }
+
         #endregion
     }