Even if you were careful in who it got sent to, it can be screen grabbed, forwarded, seen, monitored, retrieved, etc.
Not to mention that it’s so easy to make a mistake in who it’s sent to. Reply all or Outlook autofills the wrong email with someone with a similar name. Or you reply in the wrong text string.
So just be nice. Plus, it’s just not professional to write mean things.
I’m not perfect, especially on CB, but I’ve learned to be very careful at work. And when sending confidential texts to my wife.