Hi Doraemon,
The exclamation in English isn't considered rude, but it is not appropriate in a business setting or English exam. We normally use an exclamation to when we are emphasising excitement, confusion, anger, etc.
Your boss is correct that it isn't suitable, though to say it is rude is just one of the feelings a native English person will experience.
If you are writing to a friend using your personal email address then feel free to use exclamations if you want, but not in business.
Is the “!”(exclamation mark)a sign of being rude? - 2011 12 18
My colleague and I were criticized again by our picky boss for using exclamation marks when writing emails to a client.
I feel am speechless now.
Is it really wrong to write, “It was nice seeing you in at the exhibition!” or “I wish to see you soon!”?
None of my English teachers told think so.
Cannot Can I not tell say/write to friends, “I am so happy today!”?
In my opinion, using an exclamation mark means happiness and excitement, doesn’t it?
Now I have to be extremely careful when writing emails.
But I need to figure out whether the exclamation mark can be considered a sign of being rudeness.
If yes, how can it happen?