@smohyee
Sorry that I did not responded to you until now.
Using our Method Outlook Plug-in, you are able to add Activities to your Method account from the emails that are sent from Microsoft Outlook. These Activities will retain the contents of these emails in its body. Because you are using Outlook to control your email traffic then the function to Read receipts can be used.
When you are using the Read Receipt function, it is totally dependent on the receiver's server/client to honour the request. That means you could send the request, not get a reply, and have no idea what actually happened. These sorts of functions work best on a closed e-mail system.
While in Method, there is not a function to request a Read Receipt so you will not be able perform this request.