Use mailkit, add optional credentials

Author: ethanhann

src/InEngine.Core/IO/Mail.cs

@@ -1,19 +1,34 @@
-using System;
-using System.Net.Mail;
+using MailKit.Net.Smtp;
+using MimeKit;
 
 namespace InEngine.Core.IO
 {
     public class Mail
     {
         public string Host { get; set; }
         public int Port { get; set; }
+        public string Username { get; set; }
+        public string Password { get; set; }
 
         public void Send(string fromAddress, string toAddress, string subject, string body)
         {
-            new SmtpClient() {
-                Host = Host,
-                Port = Port
-            }.Send(new MailMessage(fromAddress, toAddress, subject, body));
+            var message = new MimeMessage();
+            message.From.Add(new MailboxAddress(fromAddress));
+            message.To.Add(new MailboxAddress(toAddress));
+            message.Subject = subject;
+            message.Body = new TextPart("plain") { 
+                Text = body
+            };
+
+            using (var client = new SmtpClient())
+            {
+                client.Connect(Host, Port, false);
+                client.AuthenticationMechanisms.Remove("XOAUTH2");
+                if (!string.IsNullOrWhiteSpace(Username) && !string.IsNullOrWhiteSpace(Password))
+                    client.Authenticate(Username, Password);
+                client.Send(message);
+                client.Disconnect(true);
+            }
         }
     }
 }

src/InEngine.Core/InEngine.Core.csproj

@@ -28,6 +28,7 @@
     <PackageReference Include="Goblinfactory.Konsole" Version="3.1.0" />
     <PackageReference Include="EntityFramework" Version="6.2.0" />
     <PackageReference Include="RestSharp" Version="106.1.0" />
+    <PackageReference Include="MailKit" Version="1.22.0" />
   </ItemGroup>
   <ItemGroup>
     <Folder Include="Scheduling\" />

src/InEngine.Core/MailSettings.cs

@@ -6,5 +6,7 @@ public class MailSettings
         public string Host { get; set; }
         public int Port { get; set; }
         public string From { get; set; }
+        public string Username { get; set; }
+        public string Password { get; set; }
     }
 }

src/InEngine.Core/Scheduling/ExecutionLifeCycle.cs

@@ -70,11 +70,13 @@ public void FirePostActions(AbstractCommand command)
             try
             {
                 if (ShouldEmailOutput)
-                    new IO.Mail()
-                    {
+                    new IO.Mail() {
                         Host = MailSettings.Host,
                         Port = MailSettings.Port,
-                }.Send(MailSettings.From, EmailOutputToAddress, emailSubject, commandOutput);
+                        Username = MailSettings.Username,
+                        Password = MailSettings.Password,
+                    }
+                    .Send(MailSettings.From, EmailOutputToAddress, emailSubject, commandOutput);
             }
             catch (Exception exception)
             {