1. A nasty, mean, ugly, obnoxious email normally sent/received in a work environment.
2. The email a boss sends when a subordinate makes an error.
a. Ah man, I didn't make productivity last week and my boss has been sending me nasties every day reminding me about it!
b. Kewl boss to equally groovy subordinate: "I just turned in my two weeks and am not going to have to be your boss anymore. Somebody else will be sending out the nasties."
c. WTC! I just got a nasty from my grand boss. I know he's gonna do a drop by and give me the business.