Created .nuspec file

Carbon.Email/Carbon.Email.nuspec

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<package >
+  <metadata>
+    <id>$id$</id>
+    <version>$version$</version>
+    <title>$title$</title>
+    <authors>$author$</authors>
+    <owners>$author$</owners>
+    <requireLicenseAcceptance>false</requireLicenseAcceptance>
+    <license type="expression">MIT</license>
+    <projectUrl>http://project_url_here_or_delete_this_line/</projectUrl>
+    <iconUrl>http://icon_url_here_or_delete_this_line/</iconUrl>
+    <description>$description$</description>
+    <releaseNotes>Summary of changes made in this release of the package.</releaseNotes>
+    <copyright>Copyright 2020</copyright>
+    <tags>Tag1 Tag2</tags>
+  </metadata>
+</package>

Carbon.Email/ISmtpProvider.cs

@@ -15,5 +15,7 @@ void SendHtmlMessage(string replyto,
           string cc, string subject, string htmlBody, Attachment attachment);
 
         void SendMessage(MailMessage msg);
+
+        bool IsValidEmail(List<string> excludedDomains, string email);
     }
 }

Carbon.Email/SendGridClient.cs

@@ -29,6 +29,27 @@ public SendGridClient(string host, string username, string password, int port =
             Credentials = new NetworkCredential(username, password);
         }
 
+        public bool IsValidEmail(List<string> excludedDomains, string email)
+        {
+            try
+            {
+                MailAddress mail = new MailAddress(email);
+                if (excludedDomains.Any(dom => email.Split('@').Contains(dom)))
+                {
+                    return false;
+                }
+                else
+                {
+                    return true;
+                }
+            }
+            catch (Exception e)
+            {
+                return false;
+            }
+
+        }
+
         public void SendHtmlMessage(string replyto, string from, string to, string cc, string subject, string htmlBody, Attachment attachment)
         {
             MailMessage msg = new MailMessage(from, to, subject, htmlBody);

CarbonTests/App.config

@@ -2,5 +2,6 @@
 <configuration>
   <appSettings>
     <add key="Carbon.Ioc-CarbonTests.Ioc.IExample,CarbonTests" value="CarbonTests.Ioc.Example,CarbonTests"/>
+    <add key="Carbon.Ioc-CarbonTests.Email.ISmtpProvider,CarbonTests" value="CarbonTests.Email.EmailBlocker,CarbonTests"/>
   </appSettings>
 <startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.2"/></startup></configuration>

CarbonTests/CarbonTests.csproj

@@ -52,6 +52,9 @@
     <Reference Include="System.Core" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Email\EmailBlocker.cs" />
+    <Compile Include="Email\ISmtpProvider.cs" />
+    <Compile Include="Email\EmailTest.cs" />
     <Compile Include="Ioc\Example.cs" />
     <Compile Include="Ioc\IExample.cs" />
     <Compile Include="Ioc\ContainerTest.cs" />

CarbonTests/Email/EmailBlocker.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net.Mail;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace CarbonTests.Email
+{
+    public class EmailBlocker : ISmtpProvider
+    {
+        public bool IsValidEmail(List<string> excludedDomains, string email)
+        {
+            try
+            {
+                MailAddress mail = new MailAddress(email);
+                if (excludedDomains.Any(dom => email.Split('@').Contains(dom)))
+                {
+                    return false;
+                }
+                else
+                {
+                    return true;
+                }
+            }
+            catch (Exception e)
+            {
+                return false;
+            }
+
+
+        }
+    }
+}

CarbonTests/Email/EmailTest.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Net.Mail;
+using System.Threading;
+using Carbon.Ioc;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace CarbonTests.Email
+{
+    [TestClass]
+    public class EmailTest
+    {
+        [TestMethod]
+        public void IsValidEmail()
+        {
+            ISmtpProvider p = Container.Get<ISmtpProvider>();
+            string email = "test@yahoo.com"; 
+            List<string> excludedDomains = new List<string>()
+            {
+                "sharklasers.com",
+                "gurilla.com"
+            };
+            Assert.IsTrue(p.IsValidEmail(excludedDomains, email));
+        }
+    }
+}

CarbonTests/Email/ISmtpProvider.cs

@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace CarbonTests.Email
+{
+    interface ISmtpProvider
+    {
+        bool IsValidEmail(List<string> excludedDomains, string email);
+    }
+}