[Mailman-Users] Sender not receiving messages

[Allan Trick]

Getting more reports now of other internal users (we have people 
subscribed within our firewall on our Exchange mail server as well as 
people outside with all other kinds of email addresses) not getting 
all messages.  In each case, it sounds like they get ONE message, 
whereas they're on between 4 and 20 different lists.  They should be 
getting 4-20 copies of the same message (one for each list they're 
on).  But they're only getting ONE.  I can't see anything different 
in the settings for the one successful list (not the same one for all users).

Is it possible that Exchange is trying to be helpful by not 
delivering the additional messages since they're all the same?  There 
is nothing in the Junk folder, but it seems logical that the mail 
system might be interfering with the mail delivery here.  We just 
went to Exchange; previously we were on sendmail and everything worked OK.

Allan