Eric Thomas wrote:
> On Wed, 4  Sep 1996 16:04:14 -0400  Stan Ryckman <[log in to unmask]>
> said:
>
> >Hmm. Just looked at it. Multiple "From:" appears to be legal, since it's
> >not explicitly prohibited (and text at the beginning says that multiples
> >are allowed unless explicitly prohibited).
>
> No, it says that  the meaning of multiple tags is  not defined by RFC822,
> in other words, that every programmer and every product is free to define
> it in a way that makes  sense in its particular context. LISTSERV defines
> it as "I can't  determine which of the multiple From:  fields is the real
> originator, so I won't process this message".
 
To be technical about it, the RFC says nothing about what the receiver
of a message must do with it (redistribute it, trash it, or bounce it).
The problem is more likely that LISTSERV does what you say, but doesn't
document the behavior.  Multiple "From:" are legal, we agree, and
LISTSERV can do what it wants, we agree, so I think it gets down
to documenting what it does (or does not) do.
 
Your original comment about a broken gateway passing the multiple
From: headers would not necessarily be correct; if it received them,
it should probably pass them on, since they are RFC-compliant, despite
the fact that neither you, nor I, nor LISTSERV has a clue what they
should mean.  If, however, it *generated* the second From: header,
then it would truly be broken.  Unfortunately I deleted that post
so I may be off the mark here, going from memory.
 
> >Not  only that,  RFC  822  itself contains  examples  of "From:"  fields
> >containing multiple addresses, so *that* is certainly legal.
>
> Take a look  at the "Date:" examples  and let me know how  you feel about
> the quality of the examples :-)
 
I did :-)
 
They don't even seem to qualify for the syntax (i.e., no colon in the
time fields).
 
I think that between 1982 and 1989 someone caught on to this problem,
and they re-described the "Date:" fields in RFC 1123, but gave no
examples there.  (Major changes: use 4-digit years, numeric timezones
strongly encouraged, and a note that Military timezones were completely
broken and meaningless since RFC 822 got the sign wrong!)
 
> >        From: a,b
>
> LISTSERV  doesn't support  that  brain-damage either  (which nobody  ever
> uses, it's  one of these things  that got added for  metaphysical reasons
> and  that we're  still  paying for  14 years  later).  It's very  simple,
> LISTSERV wants  ONE address from  which the command  originates. LISTSERV
> doesn't support the concept of having a command originating from multiple
> people at the same time.
 
Makes sense to me; it just should be documented.  IMHO.
 
Cheers,
Stan.