To me, the most important part of an email is the subject line. What it tells me factors into whether I read it immediately or get back to it later. Later might take months as I don’t really have the time to read my email. Same thing with tickets. Additionally, several times a week, someone will ask if anyone knows something about an issue and my email and tickets are my go-to for looking for more information about something months to years ago.
I see a lot of really generic things that are meaningless to me. These are usually from a human composing an email or ticket. Something like “Error” or “Problem.”
Formalized things usually have good subjects. Our consultant access renewal tickets have full name, email, expiration date. A++
The hard part is concise but also descriptive. Informative but not so much detail it becomes overwhelming. But, honestly, when I am having to click through 30 items looking for a possible existing needle and having to read through things to tell if any are relevant is when I wish people were more descriptive.