>The basic summary of what I found is this - Listserv has always added 
>the spaces, because the web archives use <pre> tags and the spaces 
>balance and line things up for beautification purposes.

No, LISTSERV has always added the spaces - period :-) Sorry, but in 1986
the web did not even exist as a pipe dream. I know this is a popular theory,
but the web interface has nothing to do with it.

The reason LISTSERV has always added the spaces is deceptively simple -
it was just what everyone else was doing. If you look at the examples in
RFC822, you will see that they are indented. This is optional, of course, but
it looks much better with a monospace font, which is what everyone was
using to read mail until the mid 90s.

To my knowledge, the only product that does not deal with this properly
is Outlook. Since Outlook is, by definition, the Internet standard, we have
changed LISTSERV to stop indenting the subject line in 1.8e.

  Eric