Some additional relevant info provided by an IT guru.....

>The UNIX "vacation" program, which has been in use for over 15 years, does not send vacation messages to mailing lists (which have also been used on UNIX servers for 20 years or so).  This situation is explained very simply in the UNIX manual entry for the "vacation" program:
>
>     No message is sent if the 'To:' or the 'Cc:' line does not
>     list the user to whom the original message was sent
>
>So, when our server gets email for you as part of the "xxxxxx@HRINET.ORG" list, it sees that "xxxxxx@cooper.cpmc.org" is not explicitly listed in the "To:" line, so it doesn't send out your vacation reply to thousands of people.
>
>The "vacation" program also looks for other indicators in email headers, such as "Precedence: bulk", that some listservs use to mark themselves as being mailing lists.
>
>It's amazing that this problem--which was dealt with on UNIX many years ago--has returned to haunt the more "modern" email programs.

--
===========================================================
Mr. David R. Fielder                    tel: 415.600.1600
Vice President, Research                fax: 415.600.1753
Research Institute                 email: xxxxxx@cooper.cpmc.org
California Pacific Medical Center  website: http://www.cpmc.org
2340 Clay Street,  Room 537
San Francisco, CA 94115
===========================================================

======================================================================
 Instructions on how to use the RESADM-L Mailing List, including
 subscription information and a web-searchable archive, are available
 via our web site at http://www.hrinet.org (click on "Listserv Lists")
======================================================================