We (humans) communicate through a very complex language, which most people think of as the words we use. However, our language is much more than just the words, it is also made up of the silences and pauses as well as our gestures, facial expressions and postures. The meaning behind our words can be greatly affected by all of these other factors.
For example, the words "what an idiot" can be a friendly ribbing if said with a smile and a wink, or they can be a curse if said through clinched teeth and with a slight pause after each word.
In a [group such as this] we are greatly limited as the majority of our language is not available and we are limited to only using words.
When sending email we need to remember that while we might be smiling and laughing while we type a certain phrase, the smile and laughter will not be present in the message when it is delivered. I believe that this absence of all clues outside of the words themselves is what leads to misunderstanding more often then not. This means that we should be careful to pick the words which can carry our intent on their own, devoid of all other influences. I know that I am more careful about my choice of words in email than I might be face-to-face. This is not because of any self-censorship, it is because of my desire to be understood while being limited to a crippled form of language. I also know that my choice of words still do not always carry my intent to all of the readers and I am still occasionally misunderstood.