I have searched but not found the following specific problem reported or
discussed on the Group Managers Forum.

I moderate numerous Yahoo groups for my trade association committees. I set
posting options for all groups to "reply to sender" rather than "reply to
group." I want group members to have to make a conscious choice to send a
message to the whole group (reply to all). This cuts down on everyone receiving
RSVPs for meetings and other inconsequential messages of importance only to the
original sender.

Some of the corporate members of these groups routinely use automated "out of
office" replies when they are travelling (which is frequently). Such messages
from some specific companies bypass the "reply to sender" setting and go to the
entire group anyway. This does not set up a continually repeating loop, as I
believe the auto-responders only send the reply once to each address, but it is
frequent enough to be quite an annoyance anyway. I assume some other companies
use "out of office" replies that do not bypass the "reply to sender" setting,
but I don't know this for certain.

The FROM: line of a message sent through my Yahoo groups has both the sender's
and the group's email addresses (e.g, "MyGroup@yahoogroups.com; on behalf of;
John Doe [johndoe@...]"). If I simply reply to the Yahoo groups
message, only John Doe, will receive my reply. If I "reply to all," both of
those addresses will receive my reply.

I exchanged a few messages with Eric of Yahoo Groups Customer Care, who explains
that the auto-responders are not configured properly. When I asked for details
on how to make sure they are configured properly, he referred me to this forum.

Do any of you folks have any insight as to how and why the auto-responders
bypass the sender setting, but a regular message reply does not? I suspect it
has something to do with multiple, slightly different sender parameters
identified in the internet message header, and how those parameters are
interpreted by the autoresponder differently from a regular message reply.

Do any of you know how to properly configure the auto-responders? I'm hoping
for instructions that I can share with the "offending" companies to cut down on
inadvertent "spam" for all.