should mail cc to original poster in this list

[Lawrence Chim <ychim@yallara.cs.rmit.edu.au>]

For my curiosity only :-)

In section 6.6, The Debian mailing lists, of the policy manual.  It
said:

"When replying to messages on the mailing list, please do not send a
carbon
 copy (CC - this does not mean `courtesy copy') to the original poster.
 Anyone who posts to a mailing list should read it to see the
responses."

But occasionally, I receive mails twice (one from the debian lists and
one from the poster).  Is this section still valid or I have to mail cc
to
the original poster and the list whenever I reply a mail.

Lawrence Chim,