On Tue, 8 Aug 1995 10:17:44 EDT you said:
><blush> I have a would-be subscriber sending from a site that adds a
>"Sender: postmaster@......" header to every message in addition to
>the user's "From:"  My initial " don't do that !!!"  resulted in a
>quote from RFC822 ( sec 4.4 -> 4.4.4 ) ( definitions of FROM/SENDER )
>The original reject from LISTSERV follows - How SHOULD I advise this
>user ???                       - mike
 
   This "gratuitous senderization" is certainly NOT the norm.  I can
quote from RFC822 too (see below) and say that I really doubt the
postmaster is personally sending this message for the person.
In addition, since the Sender: address is a key place for errors
to be sent the postmaster is depriving the user of error messages
by doing this.
 
   It seems to me that EVERY message from that system is probably
sent the same way which would seem to make the Sender: field
redundant and it should not be used.  In other words, RFC 822 seems
to be pretty clear that Sender is to be used for special cases.
 
   The correct use of Sender: is the way it is used by MLM's like
LISTSERV - to indicate that the mail, while it may have a user's
From: adress, is being sent by a list.
 
 
     4.4.2.  SENDER / RESENT-SENDER
 
        This field contains the authenticated identity  of  the  AGENT
        (person,  system  or  process)  that sends the message.  It is
        intended for use when the sender is not the author of the mes-
        sage,  or  to  indicate  who among a group of authors actually
        sent the message.  If the contents of the "Sender" field would
        be  completely  redundant  with  the  "From"  field,  then the
        "Sender" field need not be present and its use is  discouraged
        (though  still legal).  In particular, the "Sender" field MUST
        be present if it is NOT the same as the "From" Field.
 
   Marty
 
Disclaimer:  Obviously, these are just my opinions...