How do you avoid this? The article gives some tips:

Read your emails aloud and listen for parts that could be confusing.

For important emails, walk away from the computer and come back with a fresh perspective.

Eudora apparently has a "Mood Watch" function, which highlights volatile phrases—one, two or three red chili peppers, depending on the burn.

This is a great reminder, especially when writing pitches or cover letters. Wit can be a great tool—as long as most readers get it. Clearly, subtlety is not the soul of wit.

Read more:http://blog.guykawasaki.com/pitching_presenting_and_speaking/#ixzz0GIxXjBS2&B