Not Analyzing fields

Apart from the original 'message' field, I don't want any other fields getting analyzed.

How can this be done using mappings?

You may need to set

"index": "not_analyzed"

for all other fields which you do not want to analyze.
You need to provide more details if your requirement is something else.

 "mappings": {
        TYPE_NAME: {
        "properties": {

            "not_message_field": {"type": "string",
                   "index": "not_analyzed"
                   },

etc.