diff --git a/FabApprovalWorkerService/Clients/SmtpClientWrapper.cs b/FabApprovalWorkerService/Clients/SmtpClientWrapper.cs
new file mode 100644
index 0000000..5f71cf2
--- /dev/null
+++ b/FabApprovalWorkerService/Clients/SmtpClientWrapper.cs
@@ -0,0 +1,20 @@
+using System.Net.Mail;
+
+namespace FabApprovalWorkerService.Clients;
+
+public interface ISmtpClientWrapper {
+    void Send(MailMessage message);
+}
+
+public class SmtpClientWrapper : ISmtpClientWrapper {
+    private SmtpClient _client;
+
+    public SmtpClientWrapper(SmtpClient client) {
+        _client = client ??
+            throw new ArgumentNullException("SmtpClient not injected");
+    }
+
+    public void Send(MailMessage message) {
+        _client.Send(message);
+    }
+}
diff --git a/FabApprovalWorkerService/Models/ECN.cs b/FabApprovalWorkerService/Models/ECN.cs
new file mode 100644
index 0000000..1b1d313
--- /dev/null
+++ b/FabApprovalWorkerService/Models/ECN.cs
@@ -0,0 +1,10 @@
+namespace FabApprovalWorkerService.Models;
+
+public class ECN {
+    public required int ECNNumber { get; set; }
+    public bool IsTECN { get; set; } = false;
+    public DateTime ExpirationDate { get; set; }
+    public DateTime? ExtensionDate { get; set; }
+    public required int OriginatorID { get; set; }
+    public required string Title { get; set; }
+}
diff --git a/FabApprovalWorkerService/Program.cs b/FabApprovalWorkerService/Program.cs
index 7ece500..57c4dda 100644
--- a/FabApprovalWorkerService/Program.cs
+++ b/FabApprovalWorkerService/Program.cs
@@ -1,14 +1,12 @@
+using FabApprovalWorkerService.Clients;
 using FabApprovalWorkerService.Services;
 using FabApprovalWorkerService.Workers;
 
-using Microsoft.Data.Sqlite;
-
 using NLog.Extensions.Logging;
 
 using Quartz;
 
-using System.Data;
-using Microsoft.Data.SqlClient;
+using System.Net.Mail;
 
 WebApplicationBuilder builder = WebApplication.CreateBuilder(args);
 
@@ -21,7 +19,14 @@ builder.Services.AddHttpClient();
 builder.Services.AddScoped<IDbConnectionService, DbConnectionService>();
 builder.Services.AddScoped<IMonInWorkerClient, MonInWorkerClient>();
 builder.Services.AddScoped<IDalService, DalService>();
+builder.Services.AddScoped<SmtpClient>((serviceProvider) => {
+    return new SmtpClient("mailrelay-external.infineon.com");
+});
+builder.Services.AddScoped<ISmtpClientWrapper, SmtpClientWrapper>();
+builder.Services.AddScoped<ISmtpService, SmtpService>();
+
 builder.Services.AddScoped<IUserService, UserService>();
+builder.Services.AddScoped<IECNService, ECNService>();
 
 builder.Services.AddQuartz(q => {
     JobKey pendingOOOStatusJob = new JobKey("Pending OOO status job");
diff --git a/FabApprovalWorkerService/Services/ECNService.cs b/FabApprovalWorkerService/Services/ECNService.cs
new file mode 100644
index 0000000..dafa272
--- /dev/null
+++ b/FabApprovalWorkerService/Services/ECNService.cs
@@ -0,0 +1,78 @@
+using FabApprovalWorkerService.Models;
+
+using System.Text;
+
+namespace FabApprovalWorkerService.Services;
+
+public interface IECNService {
+    Task<IEnumerable<ECN>> GetExpiringTECNs();
+    Task<IEnumerable<ECN>> GetExpiredTECNs();
+}
+
+public class ECNService : IECNService {
+    private readonly ILogger<ECNService> _logger;
+    private readonly IDalService _dalService;
+
+    public ECNService(ILogger<ECNService> logger, IDalService dalService) {
+        _logger = logger ?? throw new ArgumentNullException("ILogger not injected");
+        _dalService = dalService ?? throw new ArgumentNullException("IDalService not injected");
+    }
+
+    public async Task<IEnumerable<ECN>> GetExpiredTECNs() {
+        try {
+            _logger.LogInformation("Attempting to get all TECNs expired in the last day");
+
+            string today = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
+            string yesterday = DateTime.Now.AddDays(-1).ToString("yyyy-MM-dd HH:mm:ss");
+
+            StringBuilder queryBuilder = new StringBuilder();
+            queryBuilder.Append("select ECNNumber, IsTECN, ExpirationDate, ExtensionDate, OriginatorID, Title ");
+            queryBuilder.Append($"from ECN where IsTECN = 1 and ");
+            queryBuilder.Append($"ExpirationDate between '{yesterday}' ");
+            queryBuilder.Append($"and '{today}'");
+
+            IEnumerable<ECN> expiredTecns = (await _dalService.QueryAsync<ECN>(queryBuilder.ToString()))
+                                        .Where(e => e.ExtensionDate is null || e.ExtensionDate < DateTime.Now)
+                                        .ToList();
+
+            _logger.LogInformation($"Found {expiredTecns.Count()} expired TECNs");
+
+            return expiredTecns;
+        } catch (Exception ex) {
+            StringBuilder errMsgBuilder = new();
+            errMsgBuilder.Append("An exception occurred when attempting to get all TECNs expired in the last day. ");
+            errMsgBuilder.Append($"Exception: {ex.Message}");
+            _logger.LogError(errMsgBuilder.ToString());
+            throw;
+        }
+    }
+
+    public async Task<IEnumerable<ECN>> GetExpiringTECNs() {
+        try {
+            _logger.LogInformation("Attempting to get all TECNs expiring in the next five days");
+
+            string today = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
+            string fiveDaysFromToday = DateTime.Now.AddDays(5).ToString("yyyy-MM-dd HH:mm:ss");
+
+            StringBuilder queryBuilder = new StringBuilder();
+            queryBuilder.Append("select ECNNumber, IsTECN, ExpirationDate, ExtensionDate, OriginatorID, Title ");
+            queryBuilder.Append($"from ECN where IsTECN = 1 and ");
+            queryBuilder.Append($"ExpirationDate between '{today}' ");
+            queryBuilder.Append($"and '{fiveDaysFromToday}'");
+
+            IEnumerable<ECN> expiringTecns = (await _dalService.QueryAsync<ECN>(queryBuilder.ToString()))
+                                        .Where(e => e.ExtensionDate is null || e.ExtensionDate <= DateTime.Now.AddDays(5))
+                                        .ToList();
+
+            _logger.LogInformation($"Found {expiringTecns.Count()} expiring TECNs");
+
+            return expiringTecns;
+        } catch (Exception ex) {
+            StringBuilder errMsgBuilder = new();
+            errMsgBuilder.Append("An exception occurred when attempting to get all TECNs expiring in the next five days. ");
+            errMsgBuilder.Append($"Exception: {ex.Message}");
+            _logger.LogError(errMsgBuilder.ToString());
+            throw;
+        }
+    }
+}
diff --git a/FabApprovalWorkerService/Services/SmtpService.cs b/FabApprovalWorkerService/Services/SmtpService.cs
new file mode 100644
index 0000000..37090be
--- /dev/null
+++ b/FabApprovalWorkerService/Services/SmtpService.cs
@@ -0,0 +1,71 @@
+using FabApprovalWorkerService.Clients;
+
+using Microsoft.IdentityModel.Tokens;
+
+using System.Net.Mail;
+
+namespace FabApprovalWorkerService.Services;
+
+public interface ISmtpService {
+    Task<bool> SendEmail(IEnumerable<MailAddress> recipients, IEnumerable<MailAddress> ccRecipients, string subject, string body);
+}
+
+public class SmtpService : ISmtpService {
+    private ILogger<SmtpService> _logger;
+    private ISmtpClientWrapper _smtpClient;
+
+    public SmtpService(ILogger<SmtpService> logger, ISmtpClientWrapper smtpClient) {
+        _logger = logger ??
+            throw new ArgumentNullException("ILogger not injected");
+        _smtpClient = smtpClient ??
+            throw new ArgumentNullException("SmtpClient not injected");
+    }
+
+    public async Task<bool> SendEmail(IEnumerable<MailAddress> recipients,
+                                      IEnumerable<MailAddress> ccRecipients,
+                                      string subject,
+                                      string body) {
+        if (recipients.IsNullOrEmpty()) throw new ArgumentNullException("recipients cannot be null or empty!");
+        if (ccRecipients.IsNullOrEmpty()) throw new ArgumentNullException("ccRecipients cannot be null or empty!");
+        if (subject.IsNullOrEmpty()) throw new ArgumentNullException("subject cannot be null or empty!");
+        if (body.IsNullOrEmpty()) throw new ArgumentNullException("body cannot be null or empty!");
+        
+        return await Task.Run(() => {
+            int maxRetries = 3;
+            int backoffSeconds = 30;
+
+            bool messageWasSent = false;
+
+            try {
+                int remainingRetries = maxRetries;
+                while (!messageWasSent && remainingRetries > 0) {
+                    try {
+                        Task.Delay((maxRetries - remainingRetries--) * backoffSeconds * 1000);
+
+                        _logger.LogInformation($"Attempting to send notification. Remaining retries: {remainingRetries}");
+
+                        MailMessage msg = new MailMessage();
+                        msg.IsBodyHtml = true;
+                        msg.From = new MailAddress("MesaFabApproval@infineon.com", "Mesa Fab Approval");
+                        msg.Sender = new MailAddress("MesaFabApproval@infineon.com", "Mesa Fab Approval");
+                        foreach (MailAddress recipient in recipients) msg.To.Add(recipient);
+                        msg.Bcc.Add("chase.tucker@infineon.com");
+                        foreach (MailAddress ccRecipient in ccRecipients) msg.CC.Add(ccRecipient);
+                        msg.Subject = subject;
+                        msg.Body = body;
+
+                        _smtpClient.Send(msg);
+
+                        messageWasSent = true;
+                    } catch (Exception ex) {
+                        _logger.LogError($"Message not sent successfully. Exception: {ex.Message}");
+                    }
+                }
+            } catch (Exception ex) {
+                _logger.LogError($"An exception occurred when attempting to send notification. Exception: {ex.Message}");
+            }
+
+            return messageWasSent;
+        });
+    }
+}
diff --git a/FabApprovalWorkerService/appsettings.Development.json b/FabApprovalWorkerService/appsettings.Development.json
index 9774599..1797133 100644
--- a/FabApprovalWorkerService/appsettings.Development.json
+++ b/FabApprovalWorkerService/appsettings.Development.json
@@ -1,9 +1,3 @@
 {
-  "ConnectionStrings": {
-    "Default": "Data Source=MESTSV02EC.infineon.com\\TEST1,50572;Integrated Security=False;Initial Catalog=FabApprovalSystem;User ID=fab_approval_admin_test;Password=Fab_approval_admin_test2023!;Connect Timeout=15;Encrypt=False;TrustServerCertificate=False; Min Pool Size=15"
-  },
-  "MonIn": {
-    "resource": "FAB_APPROVAL_WORKER_SERVICE_MES_OP_FE_TEST",
-    "workerUrl": "https://mestsa008.infineon.com:7851/"
-  }
+  
 }
diff --git a/FabApprovalWorkerService/appsettings.json b/FabApprovalWorkerService/appsettings.json
index f71b03e..1797133 100644
--- a/FabApprovalWorkerService/appsettings.json
+++ b/FabApprovalWorkerService/appsettings.json
@@ -1,12 +1,3 @@
 {
-  "ConnectionStrings": {
-    "Development": "Data Source=D:\\FabApprovalWorkerService\\LocalDb.db",
-    "Default": "Data Source=MESTSV02EC.infineon.com\\TEST1,50572;Integrated Security=False;Initial Catalog=FabApprovalSystem;User ID=fab_approval_admin_test;Password=Fab_approval_admin_test2023!;Connect Timeout=15;Encrypt=False;TrustServerCertificate=False; Min Pool Size=15"
-  },
-  "MonIn": {
-    "resource": "FAB_APPROVAL_WORKER_SERVICE_MES_OP_FE",
-    "workerUrl": "https://messa014.infineon.com:7851/",
-    "retries": 3,
-    "backoffInSeconds": 30
-  }
+  
 }
diff --git a/FabApprovalWorkerServiceTests/ECNServiceTests.cs b/FabApprovalWorkerServiceTests/ECNServiceTests.cs
new file mode 100644
index 0000000..1c66e80
--- /dev/null
+++ b/FabApprovalWorkerServiceTests/ECNServiceTests.cs
@@ -0,0 +1,217 @@
+using FabApprovalWorkerService.Models;
+using FabApprovalWorkerService.Services;
+
+using Microsoft.Extensions.Logging;
+
+using Moq;
+
+namespace FabApprovalWorkerServiceTests;
+internal class ECNServiceTests {
+    Mock<ILogger<ECNService>> _mockLogger;
+    Mock<IDalService> _mockDalService;
+
+    ECNService _ecnService;
+
+    [SetUp]
+    public void Setup() {
+        _mockLogger = new Mock<ILogger<ECNService>>();
+        _mockDalService = new Mock<IDalService>();
+    }
+
+    [Test]
+    public void EcnServiceWithNullLoggerShouldThrowException() {
+        Assert.Throws<ArgumentNullException>(() => new ECNService(null, _mockDalService.Object));
+    }
+
+    [Test]
+    public void EcnServiceWithNullDalServiceShouldThrowException() {
+        Assert.Throws<ArgumentNullException>(() => new ECNService(_mockLogger.Object, null));
+    }
+
+    [Test]
+    public async Task GetExpiringTECNsWithDbErrorShouldThrowException() {
+        _mockDalService.Setup(d => d.QueryAsync<ECN>(It.IsAny<string>())).ThrowsAsync(new Exception());
+
+        _ecnService = new ECNService(_mockLogger.Object, _mockDalService.Object);
+
+        Assert.ThrowsAsync<Exception>(async Task () => await _ecnService.GetExpiringTECNs());
+    }
+
+    [Test]
+    public async Task GetExpiredTECNsWithDbErrorShouldThrowException() {
+        _mockDalService.Setup(d => d.QueryAsync<ECN>(It.IsAny<string>())).ThrowsAsync(new Exception());
+
+        _ecnService = new ECNService(_mockLogger.Object, _mockDalService.Object);
+
+        Assert.ThrowsAsync<Exception>(async Task () => await _ecnService.GetExpiredTECNs());
+    }
+
+    [Test]
+    public async Task GetExpiringTECNsWithNoResultsFromDbShouldReturnEmpty() {
+        IEnumerable<ECN> emptyEcns = new List<ECN>();
+
+        _mockDalService.Setup(d => d.QueryAsync<ECN>(It.IsAny<string>())).Returns(Task.FromResult(emptyEcns));
+
+        _ecnService = new ECNService(_mockLogger.Object, _mockDalService.Object);
+
+        IEnumerable<ECN> actual = await _ecnService.GetExpiringTECNs();
+
+        Assert.That(actual, Is.Empty);
+    }
+
+    [Test]
+    public async Task GetExpiredTECNsWithNoResultsFromDbShouldReturnEmpty() {
+        IEnumerable<ECN> emptyEcns = new List<ECN>();
+
+        _mockDalService.Setup(d => d.QueryAsync<ECN>(It.IsAny<string>())).Returns(Task.FromResult(emptyEcns));
+
+        _ecnService = new ECNService(_mockLogger.Object, _mockDalService.Object);
+
+        IEnumerable<ECN> actual = await _ecnService.GetExpiredTECNs();
+
+        Assert.That(actual, Is.Empty);
+    }
+
+    [Test]
+    public async Task GetExpiringTECNsWithNoExtensionFromDbShouldReturnSameResults() {
+        IEnumerable<ECN> ecns = new List<ECN>() { 
+            new ECN() {
+                ECNNumber = 1,
+                OriginatorID = 1,
+                Title = "title1",
+                IsTECN = true,
+                ExpirationDate = DateTime.Now.AddDays(1)
+            },
+            new ECN() {
+                ECNNumber = 2,
+                OriginatorID = 1,
+                Title = "title2",
+                IsTECN = true,
+                ExpirationDate = DateTime.Now.AddDays(2)
+            },
+            new ECN() {
+                ECNNumber = 3,
+                OriginatorID = 1,
+                Title = "title3",
+                IsTECN = true,
+                ExpirationDate = DateTime.Now.AddDays(3)
+            },
+        };
+
+        _mockDalService.Setup(d => d.QueryAsync<ECN>(It.IsAny<string>())).Returns(Task.FromResult(ecns));
+
+        _ecnService = new ECNService(_mockLogger.Object, _mockDalService.Object);
+
+        IEnumerable<ECN> actual = await _ecnService.GetExpiringTECNs();
+
+        Assert.That(actual.Count(), Is.EqualTo(3));
+    }
+
+    [Test]
+    public async Task GetExpiredTECNsWithNoExtensionFromDbShouldReturnSameResults() {
+        IEnumerable<ECN> ecns = new List<ECN>() {
+            new ECN() {
+                ECNNumber = 1,
+                OriginatorID = 1,
+                Title = "title1",
+                IsTECN = true,
+                ExpirationDate = DateTime.Now.AddHours(-2)
+            },
+            new ECN() {
+                ECNNumber = 2,
+                OriginatorID = 1,
+                Title = "title2",
+                IsTECN = true,
+                ExpirationDate = DateTime.Now.AddHours(-20)
+            },
+            new ECN() {
+                ECNNumber = 3,
+                OriginatorID = 1,
+                Title = "title3",
+                IsTECN = true,
+                ExpirationDate = DateTime.Now.AddHours(-12)
+            },
+        };
+
+        _mockDalService.Setup(d => d.QueryAsync<ECN>(It.IsAny<string>())).Returns(Task.FromResult(ecns));
+
+        _ecnService = new ECNService(_mockLogger.Object, _mockDalService.Object);
+
+        IEnumerable<ECN> actual = await _ecnService.GetExpiredTECNs();
+
+        Assert.That(actual.Count(), Is.EqualTo(3));
+    }
+
+    // Test when responses include extension dates
+    [Test]
+    public async Task GetExpiringTECNsWithExtensionsFromDbShouldReturnSameResults() {
+        IEnumerable<ECN> ecns = new List<ECN>() {
+            new ECN() {
+                ECNNumber = 1,
+                OriginatorID = 1,
+                Title = "title1",
+                IsTECN = true,
+                ExpirationDate = DateTime.Now.AddDays(1)
+            },
+            new ECN() {
+                ECNNumber = 2,
+                OriginatorID = 1,
+                Title = "title2",
+                IsTECN = true,
+                ExpirationDate = DateTime.Now.AddDays(2)
+            },
+            new ECN() {
+                ECNNumber = 3,
+                OriginatorID = 1,
+                Title = "title3",
+                IsTECN = true,
+                ExpirationDate = DateTime.Now.AddDays(3),
+                ExtensionDate = DateTime.Now.AddDays(10)
+            },
+        };
+
+        _mockDalService.Setup(d => d.QueryAsync<ECN>(It.IsAny<string>())).Returns(Task.FromResult(ecns));
+
+        _ecnService = new ECNService(_mockLogger.Object, _mockDalService.Object);
+
+        IEnumerable<ECN> actual = await _ecnService.GetExpiringTECNs();
+
+        Assert.That(actual.Count(), Is.EqualTo(2));
+    }
+
+    [Test]
+    public async Task GetExpiredTECNsWithExtensionsFromDbShouldReturnSameResults() {
+        IEnumerable<ECN> ecns = new List<ECN>() {
+            new ECN() {
+                ECNNumber = 1,
+                OriginatorID = 1,
+                Title = "title1",
+                IsTECN = true,
+                ExpirationDate = DateTime.Now.AddHours(-2)
+            },
+            new ECN() {
+                ECNNumber = 2,
+                OriginatorID = 1,
+                Title = "title2",
+                IsTECN = true,
+                ExpirationDate = DateTime.Now.AddHours(-20)
+            },
+            new ECN() {
+                ECNNumber = 3,
+                OriginatorID = 1,
+                Title = "title3",
+                IsTECN = true,
+                ExpirationDate = DateTime.Now.AddHours(-12),
+                ExtensionDate = DateTime.Now.AddDays(10)
+            },
+        };
+
+        _mockDalService.Setup(d => d.QueryAsync<ECN>(It.IsAny<string>())).Returns(Task.FromResult(ecns));
+
+        _ecnService = new ECNService(_mockLogger.Object, _mockDalService.Object);
+
+        IEnumerable<ECN> actual = await _ecnService.GetExpiredTECNs();
+
+        Assert.That(actual.Count(), Is.EqualTo(2));
+    }
+}
diff --git a/FabApprovalWorkerServiceTests/SmtpServiceTests.cs b/FabApprovalWorkerServiceTests/SmtpServiceTests.cs
new file mode 100644
index 0000000..191ca69
--- /dev/null
+++ b/FabApprovalWorkerServiceTests/SmtpServiceTests.cs
@@ -0,0 +1,117 @@
+using FabApprovalWorkerService.Clients;
+using FabApprovalWorkerService.Services;
+
+using Microsoft.Extensions.Logging;
+
+using Moq;
+
+using System.Net.Mail;
+
+namespace FabApprovalWorkerServiceTests;
+internal class SmtpServiceTests {
+    private static readonly List<MailAddress> ADDRESS_LIST = new List<MailAddress>() {
+            new MailAddress("fake@email.com")
+    };
+
+    private Mock<ILogger<SmtpService>> _mockLogger;
+    private Mock<ISmtpClientWrapper> _mockSmtpClient;
+
+    private SmtpService _smtpService;
+
+    [SetUp]
+    public void Setup() {
+        _mockLogger = new Mock<ILogger<SmtpService>>();
+        _mockSmtpClient = new Mock<ISmtpClientWrapper>();
+    }
+
+    [Test]
+    public void SmtpServiceWithNullLoggerShouldThrowException() {
+        Assert.Throws<ArgumentNullException>(() => new SmtpService(null, _mockSmtpClient.Object));
+    }
+
+    [Test]
+    public void SmtpServiceWithNullSmtpClientShouldThrowException() {
+        Assert.Throws<ArgumentNullException>(() => new SmtpService(_mockLogger.Object, null));
+    }
+
+    [Test]
+    public void SendMailWithNullRecipientsShouldThrowException() {
+        _smtpService = new SmtpService(_mockLogger.Object, _mockSmtpClient.Object);
+
+        Assert.ThrowsAsync<ArgumentNullException>(async Task () => {
+            await _smtpService.SendEmail(null, ADDRESS_LIST, "subject", "body");
+        });
+    }
+
+    [Test]
+    public void SendMailWithEmptyRecipientsShouldThrowException() {
+        _smtpService = new SmtpService(_mockLogger.Object, _mockSmtpClient.Object);
+
+        Assert.ThrowsAsync<ArgumentNullException>(async Task () => {
+            await _smtpService.SendEmail(new List<MailAddress> (), ADDRESS_LIST, "subject", "body");
+        });
+    }
+
+    [Test]
+    public void SendMailWithNullccRecipientsShouldThrowException() {
+        _smtpService = new SmtpService(_mockLogger.Object, _mockSmtpClient.Object);
+
+        Assert.ThrowsAsync<ArgumentNullException>(async Task () => {
+            await _smtpService.SendEmail(ADDRESS_LIST, null, "subject", "body");
+        });
+    }
+
+    [Test]
+    public void SendMailWithEmptyccRecipientsShouldThrowException() {
+        _smtpService = new SmtpService(_mockLogger.Object, _mockSmtpClient.Object);
+
+        Assert.ThrowsAsync<ArgumentNullException>(async Task () => {
+            await _smtpService.SendEmail(ADDRESS_LIST, new List<MailAddress>(), "subject", "body");
+        });
+    }
+
+    [Test]
+    public void SendMailWithNullSubjectShouldThrowException() {
+        _smtpService = new SmtpService(_mockLogger.Object, _mockSmtpClient.Object);
+
+        Assert.ThrowsAsync<ArgumentNullException>(async Task () => {
+            await _smtpService.SendEmail(ADDRESS_LIST, ADDRESS_LIST, null, "body");
+        });
+    }
+
+    [Test]
+    public void SendMailWithEmptySubjectShouldThrowException() {
+        _smtpService = new SmtpService(_mockLogger.Object, _mockSmtpClient.Object);
+
+        Assert.ThrowsAsync<ArgumentNullException>(async Task () => {
+            await _smtpService.SendEmail(ADDRESS_LIST, ADDRESS_LIST, "", "body");
+        });
+    }
+
+    [Test]
+    public void SendMailWithNullBodyShouldThrowException() {
+        _smtpService = new SmtpService(_mockLogger.Object, _mockSmtpClient.Object);
+
+        Assert.ThrowsAsync<ArgumentNullException>(async Task () => {
+            await _smtpService.SendEmail(ADDRESS_LIST, ADDRESS_LIST, "subject", null);
+        });
+    }
+
+    [Test]
+    public void SendMailWithEmptyBodyShouldThrowException() {
+        _smtpService = new SmtpService(_mockLogger.Object, _mockSmtpClient.Object);
+
+        Assert.ThrowsAsync<ArgumentNullException>(async Task () => {
+            await _smtpService.SendEmail(ADDRESS_LIST, ADDRESS_LIST, "subject", "");
+        });
+    }
+
+    [Test]
+    public async Task SendEmailWithValidArgsShouldSendMailThroughClient() {
+        _smtpService = new SmtpService(_mockLogger.Object, _mockSmtpClient.Object);
+        
+        Assert.True(await _smtpService.SendEmail(ADDRESS_LIST, ADDRESS_LIST, "subject", "body"));
+
+        _mockSmtpClient.Verify(s => s.Send(It.IsAny<MailMessage>()));
+    }
+}
diff --git a/FabApprovalWorkerServiceTests/UserServiceTests.cs b/FabApprovalWorkerServiceTests/UserServiceTests.cs
index 88192ec..9e81522 100644
--- a/FabApprovalWorkerServiceTests/UserServiceTests.cs
+++ b/FabApprovalWorkerServiceTests/UserServiceTests.cs
@@ -1,5 +1,3 @@
-using Dapper.Contrib.Extensions;
-
 using FabApprovalWorkerService.Models;
 using FabApprovalWorkerService.Services;
 
@@ -9,7 +7,7 @@ using Moq;
 
 namespace FabApprovalWorkerServiceTests;
 
-public class UserServiceTests {
+internal class UserServiceTests {
     private static readonly ILogger<UserService> MOCK_LOGGER = Mock.Of<ILogger<UserService>>();
 
     private static readonly IEnumerable<User> MOCK_USERS = new List<User>() {