We need more detailed requirement about this feature. Please could you send me the message file you need to fill? What fields you need to fill? After the messages are filled, how do you send them to user?
1. How do we show the message in an outlook message window like you mentioned above?
2. We fill in using Aspose - to, cc, body, subject....
Then we would like to pop it up in Outlook New Message window so that the user can edit it and send it. Additionally, we would like to add/edit user-defined fields of email (outlook).