How to attach a downloaded and saved file on Windows PC

I received mutual insurance proof by email (Firefox browser). I was able to open it but I didn't know, I couldn't, if possible (right click or left click) save it. Is it possible to save it and how to do it?
So I downloaded it. This file is called "barbaric" jade-xV050.x-cass.......I saved the file with the name that accompanies it and I also saved it under another name        
I must contact him for a refund request. I click on the appropriate link to access said file and, there, mystery the file is not displayed. This is valid for the "designation of origin" file and also for the appellation that I created. However, in the same folder there are other files displayed.  
I check the folder concerned and the refractory file is present.

When I click on this file to open it I get the following info: "select an application to open it" I select "adobe acrobat" and can I open it? Since the file concerned does not appear when I try to attach it I printed and saved it. There was no difficulty in contacting him. Do you have the solution – how to make a downloaded, saved file join when I click "select file to send," Thank you for your explanations for a solution which, I believe, must exist