> you get mail from someone, VIA the list. The list is a
> transport, not an entity. Therefore, who you reply to should be at
> your discretion and the original sender's discretion.

When I see a mail from <...> on the list, I don't consider this a
mail from him - it's a mail from the list. The list *is* an entity, and
the day I unsubscribe from it is the day all sorts of people whom I don't
know stop sending me email.

> "mechanism, not policy". Setting Reply-To on every mailing list
> posting is certainly establishing policy! 

"mechanism, not policy" is about system programming, not about human
interaction. Human interaction needs policies (e.g., don't send ads to
linux-il!), and sometime when the machine can "enforce", or at least
"recommend" a policy, it's much more effective than stating that policy
on the "welcome to linux-il" email. I find it silly for someone to suggest
a certain policy SHOULD be on that welcome email, but refuse to recommend
that policy in the best way a list can do that: setting a Reply-To:
header.

Another example of policy is that the mailing lists I run have a filter
which catches short messages with the text "unsubscribe", and passes them
for my aproval. This means that all the silly "please unsubscribe me"
messages don't reach the list, like they do on other lists. Other policies
prevent spams from reaching my lists (again, this is something that other
lists don't do). All these policies aim to make the mailing list a friendier,
simpler, experience. Enforcing them semi-automatically (rather than only 
saying on the welcome message "please don't send spam" or "to unsubscribe,
send ...") makes these policies real, as opposed to some idealistic thing
that nobody follows (like <...> always pleas people not to CC: responses to
him).

---

In linux-il, people always send the ugly, annoying CC:s. I even got
legally threatened because of such a CC to the wrong person ;) (the
jobinfo incident).
On hackers-il, replies go only to the list.

Which is better? Most people  agree that they don't want the
extra CC to them - they'll read the reply to them in their own leasure
on the list (an exception is probably lkml, which has such a huge
traffic that you wouldn't find your responses :)).

As you can't dispute, the Reply-To: header (or lack thereof) actually
changes the behavior of people and the way they have to use the mailing list.
Effectively, the lack of Reply-To: is a *lack of mechanism* because 90%
of the subscribers don't know how (or don't care enough to) find how
to do that on their own. People on hackers-il *can* CC to the original
poster, and people on linux-il *can* remove the original poster from the
CC - but people don't bother to do either of those.

-- 
Nadav Har'El                        |      Sunday, Jan 26 2003, 23 Shevat 5763