How do you email? Have you given any thought to this? The vast majority of us haven’t, and I’m sure to some the question is nonsensical. John Gruber has some pointed thoughts on email style:
The fundamental source of poor email style is the practice of quoting the entire message you’re replying to. If that’s what you do, then it doesn’t matter whether you put your response at the top or bottom. In fact, if you’re going to quote the entire message, top-posting probably is better. But both are poor form.
Email is a back-and-forth practice, like letters. But unlike letters it is easy to copy the original text. This has been abundantly abused with an email style called “top-posting” which I agree is a terrible way to respond to email messages. Quoting the entire previous message at the bottom of an email is wasteful, ugly, and inefficient. The problem with top-posting is it misses the point of quotations:
The point of quoting isn’t to maintain a self-contained copy of the entire thread in each single message; the point is to provide context for your own remarks.
Usually there is a single statement in an email that needs to be responded to. It is much more elegant to simply include that bit at the top of your message, and then compose any statements in response below. If there are multiple responses needed, repeat. This kind of email response is much easier (and a pleasure) to read, and it is clear to the reader exactly what is being responded to.
I have to admit that I used the top-posting method out of both laziness and ignorance for at least ten years. It wasn’t until I corresponded with Gruber via email that I even knew there was a better way.