How we interpret the tone of an email and the emotional value in it, I wonder, may be a reflection of our own attitude rather than what is implied in the email. I pick up phone or show up in person where I strongly suspect email wont solve problem but might end up creating one! Nonetheless, even under normal informal conversational circumstances, people get offended by emails.
Email when used often becomes a chat like tool. Email is a name we have give to a mode of communication but what is going on is a conversation. But old habit of curtsies hardly dies; we still expect each mail to "address" us like old snail mail did! We do not say "Dear Siddu" every time we say something in a conversation. This difference in looking at E-mail becomes huge problem when unwanted emotions creep in.
E-mail over the years among a community of people creates an email culture so customized that people in that community start to believe everyone has the same set of protocol to deal with emails and expect others to behave the same way. New comes to a community feel that heat when they get angry emails apparently for no reason. This new community may be a new work place, new social circle. I am leaning to remember individual preferences when I communicate. Yet it is much easier if people relax a bit and stop attributing emotions to every word of emails. Emotions are hard to understand when communicating directly. How will that become easier on emails? Ignoring emotions will help a lot. Sensitive matters however are best dealt in person.