Yesterday I accidentally learned that you can reposition the closed captions on YouTube videos. I waa at the Smartboard talking about how the cursor and my finger were a couple of inches apart, and I accidentally dragged the captions of a YouTube video that we were watching.
I think the difference in day to day usage of the words is different. Theoretically I only ever refer to “emails” with people when I’m talking about work emails that are often in chains grouped together with the same subject. Sort of “did you see all of those emails about the forklift repair?”
Whereas with physical mail it’s always one offs, people wouldn’t have groups of mail belonging to the same subject due to the nature of snail mail, they’d have all info for the person in one piece of mail and if there’s back and forth it would just become “letters” or just papers/files at that point since the mail would already be opened and thrown away or filed away and you wouldn’t consider it mail anymore.