On 20 Mar 00, at 17:42, Melissa Riley wrote:

> We use cc:Mail as our local e-mail system (UGH!)

That's your problem. cc:Mail does not adhere to Internet mail
standards. Of all the Internet standards noncompliant mail
software, cc:Mail is the most non-compliant of all.

Mail standards require that the "envelope" specified by RFC821 be
thrown away when delivered to the final destination and that only
the mail headers on the message, specified by RFC822, be on the
email message. Instead, cc:Mail throws away the 822 mail
headers and replaces them with the 821 delivery instructions. So
the address for bounces becomes the From: address that the
recipient sees and the delivery information becomes the To:
addresses that the recipient sees.

Francoise