I need to forward (equivalent of BCC) all messages to/from a given user to another user on Exchange server 2003. Is this possible?
I can do it for inbound using How to add an email forwarding in Exchange 2003 but it doesn't apply to outbound messages.
(I also realize if the user is sending directly to another SMTP server, this would not be possible - I just need it to work when they are sending through Exchange).
You can do this for all incoming messages by configuring the delivery options on the Exchange General tab of the user properties in ADUC. AFAIK, there's no way to natively do it for outgoing messages in Exchange 2003.
In a former life I did this with public folders (long story, a bit of a kludge but it worked), but I've got a feeling the outgoing copy had to be a client-side rule.
I ended up doing this for inbound via the link in the original question, and for outbound via postfix: How do I forward outbound mail for a specific user in postfix? (I happen to run an outbound relay server that exchange sends all outbound mail through).