anchor.diff:  
   ```
   X-MSYS-API: {
  -"cc" : [
  -   {
  +   "cc" : [
  +    {
       "email" : "cc_recip_1@gmail.com",
       "name" : "CC 1"
  -   },
  -   {
  +    },
  +    {
       "email" : "cc_recip_2@gmail.com",
       "name" : "CC 2"
  -   }
  -]
  -"bcc" : [
  -   {
  +    }
  +  ]
  +
  +  "bcc" : [
  +    {
       "email" : "bcc_recip_1@gmail.com",
       "name" : "BCC 1"
  -   }
  -]
  +    }
  +  ]
   }
   ```
  +
  +## Comments on Header Length
   
   SMTP defines a maximum line length of 1000 characters (including CRLF).  If the value of the X-MSYS-API JSON string is
   longer than 998 characters, it will need to be folded across multiple lines before the message is injected.  An example
  
positive.code: | click_tracking | boolean | Whether click tracking is enabled for this SMTP message | no | Defaults to false. |
  | sandbox|boolean|Whether or not to use the sandbox sending domain | no |Defaults to false.|
  
  When submitting an email via SMTP that includes the X-MSYS-API header, you may specify a JSON array for cc, bcc, and archive lists.  For each address in each of these arrays, a message will be generated. Messages will be generated with the following headers: 
  * It is the responsibility of the user to include their own "To" header in the body of the message.
  * All messages will display the Cc header and the value of that header will include all addresses listed in the “cc” array.
  * The “bcc” and “archive” recipients will each receive a message with the To and Cc headers described above and, additionally, will see a Bcc header with ONLY their own recipient address as the value of the header.
  
  
  **What is an archive recipient?**
  
  Recipients in the “archive” list will receive an exact replica of the message that was sent to the RCPT TO address. In particular, any encoded links intended for the RCPT TO recipient will appear “as is” in the archive messages.  In contrast, recipients in the “bcc” list will have links encoded specific to their address. (Note: There will be some differences in headers such as X-MSFBL or List-Unsubscribe headers, etc.)
  
  For example:
  
  ```
  X-MSYS-API: {
  
  “cc” : [ “cc_email1@corp.com”, “cc_email2@corp.com” ], 
  “bcc” : [ “bcc_email1@corp.com”, “bcc_email2@corp.com” ], 
  “archive” : [ “archive_email"@corp.com” ], 
  
  "options" : {"open_tracking" : false, "click_tracking" : true},
  }
  ```
  NOTE:  You may not specify more than a total of 1000 total recipients in those 3 lists.
  
negative.code:     }
      ```
  
  # Group SMTP API
  
  Through use of the X-MSYS-API header in a message sent to SparkPost through SMTP 
  (see ["Sending an Email"](https://www.sparkpost.com/docs/sending-email)), you can now specify a campaign id, metadata,
  