Ability to apply a CC address

src/Postmark.Tests/ClientSendingTests.cs

@@ -43,6 +43,28 @@ await _client.SendMessageAsync(
                 "If it has been more than 45 days since these tests have been run on this server, try re-running this test."
             );
         }
+
+        [Fact]
+        public async void Client_CanSendASingleMessage_With_CC()
+        {
+            var result = await _client.SendMessageAsync(WRITE_TEST_SENDER_EMAIL_ADDRESS,
+                WRITE_TEST_EMAIL_RECIPIENT_ADDRESS,
+                String.Format("Integration Test - {0}", TESTING_DATE),
+                String.Format("Plain text body, {0}", TESTING_DATE),
+                String.Format("Testing the Postmark .net client, <b>{0}</b>", TESTING_DATE),
+                new Dictionary<string, string>()
+                {
+                    {  "X-Integration-Testing" , TESTING_DATE.ToString("o")}
+                },
+                new Dictionary<string, string>() {
+                    {"test-metadata", "value-goes-here"},
+                    {"more-metadata", "more-goes-here"}
+                }, cc: WRITE_TEST_EMAIL_RECIPIENT_ADDRESS);
+
+            Assert.Equal(PostmarkStatus.Success, result.Status);
+            Assert.Equal(0, result.ErrorCode);
+            Assert.NotEqual(Guid.Empty, result.MessageID);
+        }
 
         [Fact]
         public async void Client_CanSendASingleMessage()

src/Postmark/Model/PostmarkMessage.cs

@@ -23,8 +23,9 @@ public PostmarkMessage()
         /// <param name = "headers">A collection of additional mail headers to send with the message. (optional)</param>
         /// <param name = "metadata">A dictionary of metadata to send with the message. (optional)</param>
         /// <param name="messageStream">The message stream used to send this message. If not provided, the default transactional stream "outbound" will be used. (optional)</param>
+        /// <param name="cc">An email address for a CC recipient.</param>
         public PostmarkMessage(string from, string to, string subject, string textBody, string htmlBody,
-            HeaderCollection headers = null, IDictionary<string, string> metadata = null, string messageStream = null) : base()
+            HeaderCollection headers = null, IDictionary<string, string> metadata = null, string messageStream = null, string cc = null) : base()
         {
             From = from;
             To = to;
@@ -34,6 +35,7 @@ public PostmarkMessage(string from, string to, string subject, string textBody,
             Headers = headers ?? new HeaderCollection();
             Metadata = metadata;
             MessageStream = messageStream;
+            Cc = cc;
         }
 
         /// <summary>

src/Postmark/PostmarkClientExtensions.cs

@@ -25,15 +25,16 @@ public static class PostmarkClientExtensions
         /// <param name="htmlBody">The HTML Body to be used for the message, this may be null if TextBody is set.</param>
         /// <param name="headers">A collection of additional mail headers to send with the message.</param>
         /// <param name="messageStream">The message stream used to send this message.</param>
+        /// <param name="cc">An email address for a CC recipient.</param>
         /// <returns>A <see cref = "PostmarkResponse" /> with details about the transaction.</returns>
         public static async Task<PostmarkResponse> SendMessageAsync(this PostmarkClient client,
             string from, string to, string subject, string textBody, string htmlBody,
              IDictionary<string, string> headers = null,
              IDictionary<string, string> metadata = null,
-             string messageStream = null)
+             string messageStream = null, string cc = null)
         {
             var message = new PostmarkMessage(from, to, subject, textBody, htmlBody,
-            new HeaderCollection(headers), metadata, messageStream);
+            new HeaderCollection(headers), metadata, messageStream, cc);
             return await client.SendMessageAsync(message);
         }