I have booked paris to zurich via the eurail website ,  and i can see the details of the reservation in the eurail app as well. However email from eurail says the eticket needs to printed out and shown at the time of travel. Can't I use the QR code in the eticket on my phone ? 

Do I need to anything additional on the eurail app  like saving journey and adding ticket manually before boarding the train, checking as I can see comments like that in the forum however was not clear.

Also the email said that we need to show the eurail pass to the conductor ,  what do they check the email/order details from eurail when the pass bought which got pass details ?

any help this will be much appreciated.