philblog tells about how Mozilla Thunderbird has its default reply position at the bottom of the email.
It bugged me too. Here’s what he said about it:
Apparently replying at the bottom of an e-mail is not an acceptable practice because I seemed to have either confused, annoyed, irritated, or all three, several people by doing so. After a few e-mails and instant messages from people I figured I would check to find out if there was a way to change this. After a brief Google search I found the solution to setting the reply position on e-mails to the top instead of the bottom.
# In Thunderbird: Go to “Account Settings”
# Select “Composition & Addressing” for the account in question
# Check the checkbox in the Composition group that says “Automatically quote the original message when replying”.
# Once the combo box below is enabled select the option “Start my reply above the quote”
That did the trick. If you use Thunderbird, or are going to try it: do this!