We have a problem with email potentially being viewed by directors PAs, which we need to protect, the situation is as follows:
Director A wants to send an email to Director B, both director A and director B have PAs, who we will call PA A and PA B.
Director A and B both give PA A and B acccess to their mail, so that they can read email and reply for them, create calendar entries etc when necessary, however, there are instances where the directors want to send emails between themselves that the PAs should not be allowed to read.
To further complicate matters, if the directors reply to the emails, we want to ensure that they can't see the replies in sent items etc.
We're running Exchange 2007 servers, outlook 2007/2010 and some of the directors also have ipads (to further complicate matters).
Any ideas as to how we can secure such communications?