It's easy to tell, Fred. Just look at your post in any web browser.
Start with:
http://www.wikipedia.org/pipermail/wikien-l/2003-April/date.html
For examples of unwrapped email that scrolls of the side of the page,
see:
http://www.wikipedia.org/pipermail/wikien-l/2003-April/002283.html
http://www.wikipedia.org/pipermail/wikien-l/2003-April/002300.html
http://www.wikipedia.org/pipermail/wikien-l/2003-April/002313.html
(Just random examples from the top of this month's list).
Yours, by the way, are fine. It's only about one poster in 20, and
sometimes posts that quote the un-wrapped ones as well. Mostly, I just
ignore the post unless it seems particularly important. But it's a
reasonable guess that, human nature being what it is, most of the
others who read the list via the web interface do the same: i.e.,
ignore non-wrapped posts because they are too hard to read.
(PS: to anyone wanting to fix the problem. It is usually very easy.
Most (all?) email clients have an option to wrap text. Look for it in
"tools" or "options" or "preferences".)
Tony Wilson
(Tannin)