It is better to put the most recent correspondence on the
top, reverse chronological filing. Why many think
scrolling to the bottom of each message makes sense,
doesn't for me. If one is exchanging letters with others
would you put the most recent letter on the top, or bottom
of the pile? If you select the bottom, every time you made
reference to it you would need to pick up the pile and pull
the bottom letter; in a business environment, chaos.
If you have perfect memory and never get confused by anything
and remember EVERYTHING everybody says, and recall references to
links made 20 posts earlier by someone who only posted once ever
so s/he is not a friend of yours, then fine. But I don't know
many people like that.
One of the things that made text Usenet great (when it /was/
great instead of crippled and slowly being killed off) was that
you could engage in interesting (or stupid) threads, and it is
much easier to keep LOGIC /logical/ when it is in FORWARD
chronological order.
Also, you don't leave posts in their entirety. You reply to what
you feel needs a comment, right below, and you <SNIP> what is
not relevant or IYO unnecessary for further discussion.