e-mail formalities

In chapter 19 of "Communications and Cyberspace," Judith Yaross Lee writes about how communication via e-mail is its own type of communication and is more informal than most other forms of communications. I do find this to be true, but to an extent. I think the formality level depends on who the sender is writing to. If I am writing a letter to a professor here at Fordham University, I always make sure I use proper greetings and endings, and always check to make sure grammar and spelling are correct in my e-mail. On the other hand, If I am writing to a close friend I usually get a little careless with spelling and grammar and use abbreviations and other phrases that I would never consider using if I was writing to a dean or professor here at Fordham. Lee states that even in e-mails that are meant to be formal there is a common omission of an opening greeting and a proper closing good-bye phrase, but I would attribute it to the way the sender writes normally rather than to the fact that he or she is using e-mail to communicate. Though I do agree with some of the points made in her writing, I do not believe that e-mail should be considered less formal than most other forms of communication because every sender has a different style of writing.