IMO, I think the best practice is to not send the original email back.
Cut and past any specific passage to which you are specifically replying
from a long post if you must, but otherwise just post.

Most, or at least half of the people do this anyway, so you have to read
individual posts to track a thread.

The total size of the archive is probably about 40% or so returned
posts.  I may be more than that.  Sometimes one post ends up have 5 or 6
posts strung together in it.  Often threads are 80% old posts because of
the returned posts and the particular people who are posting.  With
programs like gmail that will cluster posts - and all will in some way
or another, there is no need to return the post to which you are replying.

If the archives weren't so bloated from repetitive return of  posts in
threads, they could be searched much faster.

Sam

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Sam Walters

Baltimore, MD