[Mailman-Users] what constitutes spam?

Brad Knowles brad at shub-internet.org
Sat May 19 23:15:39 CEST 2012

On May 19, 2012, at 4:13 AM, Anne Wainwright wrote:

> Thanks for clarifying that, Brad, I wasn't sure what the import of
> Mark's messsage was.
> Why would this not be set to 'list' rather than 'bulk'?

According to RFC 2076, the "Precedence:" header is "Non-standard, controversial, discouraged."  RFC 3834 says:

>    -  A responder MAY refuse to send a response to a subject message
>       which contains any header or content which makes it appear to the
>       responder that a response would not be appropriate.  For instance,
>       if the subject message contained a Precedence header field
>       [I4.RFC2076] with a value of "list" the responder might guess that
>       the traffic had arrived from a mailing list, and would not respond
>       if the response were only intended for personal messages.  For
>       similar reasons, a responder MAY ignore any subject message with a
>       List-* field [I5.RFC2369].  (Because Precedence is not a standard
>       header field, and its use and interpretation vary widely in the
>       wild, no particular responder behavior in the presence of
>       Precedence is recommended by this specification.)


> 3.1.8.  Precedence field
>    A response MAY include a Precedence field [I4.RFC2076] in order to
>    discourage responses from some kinds of responders which predate this
>    specification.  The field-body of the Precedence field MAY consist of
>    the text "junk", "list", "bulk", or other text deemed appropriate by
>    the responder.  Because the Precedence field is non-standard and its
>    interpretation varies widely, the use of Precedence is not
>    specifically recommended by this specification, nor does this
>    specification recommend any particular value for that field.

Historically, the "Precedence:" header has generally only had one standard value that I know of, if it was used at all -- and that value is "bulk".  The original intent of this header (and this setting) was to help automated systems that receive mail messages to determine whether or not a message was originated by a human being or was perhaps automatically generated or handled through a mailing list -- at the time, there was no such negative connotation to the word "bulk" and no one would have distinguished between "bulk" mail and mail sent through a "list".

Over the years, things have changed, but the usage of this particular header has only gotten murkier.  Mailman is one of the few programs on the Internet that has been fairly consistent in the way it has handled this header.

Of course, Mailman is only handling one end of the conversation, and it can't control what people on the other end do with the header.  If we change the way Mailman works in this regard, we might break existing programs.  If we don't change the way Mailman works in this regard, people on the other end might not understand what is really intended.

Brad Knowles <brad at shub-internet.org>
LinkedIn Profile: <http://tinyurl.com/y8kpxu>

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