Sent emails getting to all users

Hello,

I am setting up a new user in a client of mine who has SBS 2011 with exchange server.

At this point the new user can access the OWA, send/receive emails to internal/external addresses, and hi can see the emails sent to the rest of the users, but he cannot see the emails that the rest of the users send.

The users are all in the same group. How do I solve this?

Any help will be greatly appreciated.

Thank you in advance.