> It's the repeated exclamations (!!) that are the true offenders.

A lawyer I know told me, about 25 years ago (before email was really common place everywhere), something I never forgot. I'm paraphrasing but it went like this:

"When a would-be client sends me a letter with some words or a sentence written in a size 16 font in bold red characters and ends the sentence with three exclamation marks, I refuse that person as a client. They're impossible to deal with. They're people convinced they're always right and you cannot make reasoned arguments to these people.".