I have one employee who doesn't use punctuation, capitalization, or even whole sentences. She breaks everything up with dashes. It's very difficult to understand what she is saying or when she has a question.
When I corrected her, she started crying, saying that she used to win all sorts of writing competitions! I'm thinking 'in what country?' And 'competition must have been slim!'
Not an email but I had an employee who would write his formal report like that! Dude never met a "period" in his entire life! Drove me nuts. I had to ask him if they taught him to write like that in college!
But back on topic...
People who feel the need to cc: half the company on every email. Is it a CYA thing, look at me...what ever the reason it's annoying.