To create message type we have WE81 transaction not SE81 which you have mentioned moreover ALE is use to transfer the data from 1 server to other server in SAP , it's not use to transfer the data from SAP to NON SAP. Please be sure that the information you share is correct.
I am really worried about how to understand idoc.. you simply cracked with lunch box.. mindblowing example and most understandble way.. thanks a lot.. keep up the good work with relative example people conncet easily