I'm usually omitting the recipient's name, even though I understand that for some people it may sound rude.
Exception: replies to email threads with multiple recipients, CC'ed people.
Same with the footer, unless I'm expecting this person to call me, so I'll be adding my phone number there.
For long emails, I'm adding TL;DR in the first lines of the email body.
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[1] https://hbr.org/2016/11/how-to-write-email-with-military-pre...
[2] https://en.wikipedia.org/wiki/High-context_and_low-context_c...