The thing is: I was employed as a senior expert!
Both "senior" and "expert"!! Wow! I never saw these words used together, this is a first.
Anyway, in a professional / corporate environment, communication is bound to certain rules. While the list of rules is not written in stone, and it may vary from company to company, they are usually the same: send the message only to the interested / relevant people, make it clear who is the recipient of the mail (the "to:" list), which are the people which are only informed (the "bcc:" list), do not forget important people from the message, keep confidential information confidential, etc.
It's this type of thing: a lot of them.
Well, a "senior expert" doing a lot of communication mistakes, is not very professional, and not very pleasant for anyone. You described yourself several mistakes you are "guilty" of:
"replied all" and didn't limit the big (=8) number of people in cc
next time ... excluded somebody
put 2020 in an email, instead of 2021
Even though apparently small, these mistakes add up.
things that are so insignificant
One thing / mistake which is insignificant remains insignificant. Even a few of them, remain insignificant. But when they become "a lot of them", things change. To understand better what I mean, read about the 1000 cuts torture and the water drop torture. One small cut is not much (I accidentally cut the skin of my fingers often, while working in the kitchen), and a water drop is nothing. But when there are "a lot of them", things become different. From the water torture page:
"The creepiest thing that happened after we did this episode was that I got an email from someone from a throw away account. He said, 'We found that randomizing when the drops occurred was incredibly effective. That anything that happens on a regular periodicity can become a type of meditation, and you can then tune it out. If you couldn't predict it, he-said, 'We found, we were able to induce a psychotic break within 20 hours.'"
And that is exactly where you are: you are always original with the mistakes.
I am accurate, compared to others even more accurate
Well, you might be more accurate than others, but the others are (most likely) not "senior experts". The expectations are different. One cannot expect from a fresh graduate the same level of quality, compared to a "senior expert".
How to react to her constant lecturing on small things, which frequently don't even make logical sense?
- Be more careful, and make less mistakes - ideally, no mistakes at all.
- If the "lectures" do not make sense, then ask your manager to be more explicit. The best would be if the manager could provide you with examples. If the manager does not provide examples by her own initiative, do not be afraid to ask. Next, be sure to act on the explanations and on the examples, and stop doing avoidable mistakes.
- Before sending the message, re-read it - once, twice, as many times as needed. Hunt for small mistakes. Hunt for big mistakes. Hunt sentences which can have more than one meaning and correct them. Avoid ambiguous words (maybe, sometimes, eventually...). If there is a colleague you can trust, ask your colleague to read your message before sending, hunting for mistakes.
- Make sure that the message does not sound aggressive, offensive or angry. If it does, re-write it. If it still sounds aggressive, re-write it again. If you cannot write it without triggering a conflict, delete it and do not send it. Find another way of communication.
Example from my own life
As a matter of fact, that is exactly what I did about 1 year ago. Something unexpected happened. I walked around the building for about 30 min to calm down as much as possible. I wrote an e-mail as a reaction. It was too aggressive, so I deleted it and wrote another one. It was still aggressive. I deleted it and stopped writing. I called the colleague - and because we could not find an agreement over the phone, we decided to postpone the discussion. We found a way around the problem. After several months when we could meet face to face, we re-opened the discussion face-to-face and clarified all the details. No reply-to-all, no forget-a-recipient - actually, no proof of any discussion at all. And the problem was solved too.