Strange one. Have exchange 2003 running on SBS server. Mail is collected by pop3.
if a mail i sent to a recipient and anyone is CC’d in. or the as a test the sender just cc’s the recipient then the email does not show any one in the CC field.
It does however work internally. At first i thought this was an issue with the Pop3 provider, so to check set up a SMTP connector and ran a telnet. i ran through some example syntax to send a CC mail to a local use. the mail arrived but showed nothing in the cc field.