Email has the ability to provide proxy access.
The process allow you the holder of the email box to give rights to others to access your email system.
Typically this is done to give a secretary access to an administrators Calendar.
It can be done in mentoring situations as well.
The process is simple. Log into the client and select tools >> options from the menu.
Double Click on Security
The click on the Proxy Access Tab
Click on the Address Book and Locate the Person you wish to give access to.
Double CLick on the Name and they will be moved tot he right hand window then click OK
To give the person rights, click once on their Name then check the appropriate boxes.
to give that person access to your calendar to check an make appointments check on Read and Write for Appointments
To give access for the other person to read your emails check Read for Mail / Phone
Note that person will have access to read all of your incoming mail.
The person who need to access your email system then selects Proxy...
from the bottom of the Online pull down Link
Then they add your name to their proxy list.
The Owner of the Mail box is the only person who has rights to give access to someone else at the email system level.