Ed Skinner wrote:
> I want to send Email to a bunch of folks but don't want
 > them to know who the others are. (It's advertising.)

The first suggestion is to make sure none of the recipient
addresses contains a 'v'.   ;-)

 > I can put all the recipients in the BCC list

I also agree that BCC is not the way to go.  Invest in one
message per recipient, and keep it open.  Otherwise a lot
of the recipients will block the message because BCC has
come to mean spam:  the first rule in spam control generally
is to throw it away if your name does not appear in a
"To" or "Cc" header, unless you recognize the sender or
reply-to address.

 > but what can I put as the To: address?

<undisclosed-recipients> is what I've seen.  It's spammish
for <none-of-your-business>.  But just don't use CC.

> Also, I need to insert  a Reply-To field in the header

I used "mailx" on a Sun box for simple automated mailing,
but where I needed to use attachments I used CPAN's
Mime::Lite package -- it was excellent, and it allowed
me to specify the Reply-To.  Just plain "mail" was less
useful, I forget why.

Mail clients are very inconsistent about what "reply" means,
so you should probably set your "Sender" to agree with
where you want replies to go.

Sendmail on the command line is a good way to send simple
mail.  I think the -r argument sets the "Sender" address.
Without Mime::Lite, I was unable to set Reply-To.

Review the RFC regarding the From<blank>, From:, Sender:
and Reply-To: headers.  This stuff is little understood.

Vic