[comp.mail.sendmail] Suppressing duplicate copies in mailing lists

hubert@blake.acs.washington.edu (Steve Hubert) (12/22/89)

I am using the usual trick of invoking a separate sendmail process from
the aliases file for sending to members of a mailing list.  The reason
for that is so that errors will be returned to the list maintainer instead
of to the sender of the message.  That works fine.

I have lists with the property that a single user may appear in both listA
and listB and people will want to send mail to the union of listA and
listB.  When this is the case, any user who is a member of both lists
will get duplicate copies of the message.  I would like to have a way
to suppress the duplicates without destroying the error processing
mentioned in the first paragraph.  Anyone managed to do that?

Thanks,
Steve Hubert, Networks and Distributed Computing, Univ. of Wash., Seattle
hubert@cac.washington.edu