Do you send emails in literate, properly spelt English, broken down into crisp, relevant paragraphs, signed at the end, even with the mandatory extra space inserted after each full stop?
If you do, you are almost certainly old. How old? From a not hugely scientific study of everyone I happen to know, I’d say over 40, but more likely 10 years north of there.
What are the tells that make a speedy, clear, informative email the mark of advancing years?
Well, the main one is that you are emailing at all. For reasons I fail to understand (but then I am quite old) most of my younger friends prefer the cumbersome, hit-and-miss messaging of social media sites, or to use fiddly phone messaging utilities such as WhatsApp. They reserve the directness and unambiguousness of email for writing to, well, old people.