[SLL] List ID (was: To Xen or not to Xen)

[johnbaxterlists at mac.com]

On Sep 12, 2007, at 5:24 PM, Andrew Sweger wrote:

> On Wed, 12 Sep 2007, Bill Campbell wrote:
>
>> I just found another reason to use the ``List-Id:'' header in
>> preference to From: etc. when Jesse Cc'ed me on his post to this
>> list.  Two copies came into our system here, the one to the list
>> went into my bulk mail folder while the Cc: one went into my
>> general folder where I saw it first as I don't always get to the
>> bulk folder quickly.
>
> Exactly! I wish that mailman permitted setting the List-Id  
> explicitly so
> it could survive relocations. Or used a GUID or some such. If it  
> can, I'm
> not seeing it (and no one but us nerds would care anyway). I mean,  
> what's
> the point of an identity if it keeps changing? That may be a  
> rhetorical
> question (so, no worries, Mitch, I truly appreciate what you're  
> doing).

This list is *so* educational.  This late afternoon, I have learned  
that the List-* headers are defined in RFC 2369 (I knew that, except  
I keep forgetting the number), EXCEPT THAT List-Id is defined in RFC  
2919 (which I hadn't known about).

The (somewhat old) version of Mailman which I use lumps them all  
together as "RFC2369" headers.  And as you say does not provide a  
means to deal with List-Id: independently.  (It doesn't provide  
control over the content of the others, either, although it does  
provide for omitting List-Post for lists to which the general  
membership shouldn't post--that was an afterthought.)

RFC2919 says:

4. Persistence of List Identifiers

    Although the list identifier MAY be changed by the mailing list
    administrator this is not desirable.  (Note that there is no
    disadvantage to changing the description portion of the List-Id
    header.)  A MUA may not recognize the change to the list identifier
    because the MUA SHOULD treat a different list identifier as a
    different list.  As such the mailing list administrator SHOULD avoid
    changing the list identifier even when the host serving the list
    changes.  On the other hand, transitioning from an informal
    unmanaged-list-id-namespace to a domain namespace is an acceptable
    reason to change the list identifier.  Also if the focus of the list
    changes sufficiently the administrator may wish to retire the
    previous list and its associated identifier to start a new list
    reflecting the new focus.


I will suggest on the Mailman-users mailing list that some future  
Mailman provide sufficient control that the above part of RFC2919 can  
be followed.  (That won't happen in the version which should emerge  
this year.)

   --John