Attachments appear at the end of an email.
To view or play the attachment, tap it.
If you see a message that you can't open the attachment type, most file types have a free viewer that you can use. In Play Store, search for the file type, then select and download an app.
In the email, tap 

To view attachments later, open the Files app (go to Download) or the Drive app.
Do one of the following:

Attached photos or videos appear as thumbnails, showing a preview.
To see a generic thumbnail instead of a preview thumbnail until you open the file:
