I've read information that shows communication split as follows: 1/3 is what a person says (the words), 1/3 how it is said (voice tone) and 1/3 how a person appears while speaking (body language/facial expressions). So with electronic communication, it's easy to see why things may be misinterpreted since approximately 2/3 of the intended communication is missing.
I send out anywhere from 75-100 emails per day at work. Not all of them are worded correctly...gasp. Thankfully, co-workers call to clarify things before jumping to conclusions. I also work in an environment where immediate responses are necessary. So emailing starts at around 6a and ends around midnight on a good day.
On another note, It's unfortunate when people take advantage of the anonymity of the internet by being rude.
FreeChick