> I have noticed that there are some mail user interfaces which seem to
> use the return-path tag for default replies, instead of the reply-to
> tag.  Thus, the user's reply goes to owner-LISTNAME, gets flagged as
> an error, and sent to the listowner.   I have told the users that
> unless they fix it, their messages will not be posted.
 
This problem seems to be particular for Banyan Vines mail systems. At least that
is my experience. Greetings, Kooi.