Sending a message that isn't forwarded by server

[smurfhell]

I have a user that receives a lot of email each day, but, since he doesn't go through it all, we have his account set to forward copies to his assistant.(Exchange General>Delivery Options>Forward To: & Send to forwarding address and mailbox)
This user needs to receive some confidential information that isn't forwarded to his assistant. What would be the best way to accomplish this?
[This user is an executive, so it should be very simple and nothing different from what he's been doing]

 

[smurfhell]

We solved this problem by signing up for a free email certificate from Comodo. The 3 other principals also got installed free certificates. When they want to send something confidential, they encrypt the message. No record of the message shows up on the assistants computer.