The discussion on Spurious mail has ignored one significant problem
and that is the announcements of new lists.  I am not going to look
for an offender right now (and do not want to single anyone out) but
many many of the announcements are unclear, ambigous, or wrong about
SUBs and SIGNOFFs.  Mostly you see that the SUB is correctly described
as having to go to LISTSERV@wherever but often the SIGNOFF is mistakenly
(either directly or by context) described as going to the list and not
the [log in to unmask]
 
Hence maybe the listowners/announcers should be given a standard text
file that can be edited to replace the list's name but otherwise is
CORRECT for the user.  And some sort of nasties from SOMEONE if they
do not use it in the announcement.
 
Pitty the poor user who reads the announcement, joins the list, rereads
the announcement and sends the spurious mail because the announcement
is wrong - but the poor user is blamed for not reading ALL the
documentation about what he is using!
 
Bob