On 16.01.2014 13:11, Reindl Harald wrote:

i get really tired of such amount of no clue

*this* is the RFC for mailing-list-headers

http://tools.ietf.org/html/rfc4021#section-2.1.35 [1] http://tools.ietf.org/html/rfc2369 [2]

*these* are the list-headers of the roundcube list

Those RFC's do not spell out what a mail client is supposed to do exactly with each of these fields. They just provide some information.

List-Id: Roundcube Users mailing list <users.lists.roundcube.net>

These headers are not present in a direct reply to a mailing list posting; they are only present in the list copy.

They can be useful in some obvious ways. For instance, suppose a lurker subscriber is tired of receiving all this off topic crap from the RCU list.

The headers can be used in the mail client to provide an easy unsubscribe feature. When the software is displaying an e-mail with this header:

List-Unsubscribe: http://lists.roundcube.net/mailman/options/users,

It can generate some "click here to unsubscribe from the list" type UI or whatever, using the URL.

This is useful because noobs often send postings like "please unsubscribe me from this list" to the list remailing address.

In the past, before these headers, lists would put footers in every message with the unsubscribe info. (Yet somehow, people still can't find it.)

We can remove these footers these days and rely on the headers.

If we regard a mailing list generated message as an object, it's good for that object to have some standard properties related to the list and not ad-hoc text in a footer. At least in theory: the question is what properties for what purpose. The RFC proposes a bunch to "cover all the bases", but it's not clear how all of them would be used.

Here is a nice use case for the List-Post: header.

I could hack my mail client to notice when Reply-To: is set to the list address (Reply-To: contents match the List-Post: contents). This strongly indicates that the list is doing reply-to munging, and the client could automatically fix the situation by scrubbing out Reply-To:, and adding the list address to the Cc:. Without this header, it would be very hard to do this reliably. So these headers can be used to combat the Reply-To disease. What a nice thing!

*any* sane list on this planet have them

Yes. For instance the list to which I was having trouble replying (in the root posting of the thread) has these headers too.

The presence of these headers is not a magic potion that fixes broken client behaviors and rude mailing list behaviors.