I am sorry to say that, but I don't think that this is possible.
A survey template consist of a list of questions and possible answers, all maintained as configuration records in the DB.
The "message template" to "message body" evaluation process is not able to incorporate the "survey template" data into the actual email message body.
The only way, I am aware of, to create a submitable survey form is by clicking on a link, which calls a specific method in the webengine, which creates the actual survey form from the given survey template id , specified in the link , beside other parameters.
Regards
...........Michael