It has been my experience that what you want is controlled
by both LISTSERV as well as the receiver's e-mail system,
sometimes at cross-functions i.e., just because you change
your list's definitions does not mean that all users will
see the same thing in their in-basket.  I can practically
guarantee that none of what you do will do what you want
for all users PLUS you will probably start a meta discussion
about it.
 
Checkout the Owner's manual on * REPLY-TO= and SENDER= ...
 
***************************************************
* Reply-To= <destination>,Respect | Ignore | Both *
***************************************************
 
Indicates whether the "Reply-to:" tag supplied by the sender of the mail file is
to be preserved or discarded (if present), and, if discarded or omitted, what
should be placed in the new "Reply-to:" generated by the server. The default
value is "List,Respect". Note that some mailing systems are unable to process a
"Reply-To:" field with multiple addresses correctly and may therefore disregard
the "Reply-to= Both" option and treat it as "Reply-to= List".
 
    Respect:   The original "Reply-to:" tag, if any, is kept.
    Ignore:    The original "Reply-to:" tag is ignored and discarded.
 
*********************************************************************
* Sender= LIST | NONE | "<list title> <net-address>",<ietf-address> *
*********************************************************************
 
Used to define the value LISTSERV will place in the RFC822 "Sender:" field.  The
second parameter is optional, and is included to allow the specification of a
second mailbox for use with IETF headers.  The first value is used for non-IETF
headers and is expected to contain the name and address of the list, or the
keywords LIST or NONE.  The second mailbox is used for IETF headers; if it is
omitted, the generic "owner-<listname>" mailbox is substituted.  Example:
 
    * Sender= "Test List <[log in to unmask]>",[log in to unmask]
 
Note that the first address must be contained in quotes.
 
/Pete Weiss at Penn State