In another article I spoke about how to create a mailbox in PHP - this article covers how to setup Exchange to have a shared mailboxes so that the same account can view all - including calendars.
If it is your goal to have an account that can view everyone else's mailboxes (this includes task lists and calendar information) then you will need to create a special sort of account.
The first step is to create a new user that will be used as the "postmaster". To do this go to the Active Directory Users and Computers window which can be accessed by clicking Start -> Settings -> Control Panel -> Administrative Tools -> Active Directory User and Computers. In the newer Windows XP / 2003 Server style menu you may find that the Administrative Tools menu is already snapped onto the menu, or that the Control Panel is (rather than being got at through Settings).
Once you are in the AD Users and Computers page goto the Users folder, right click, goto New new and then select "User...". Set this user up with a password of your choice, tick the boxes to specify that the user cannot change their password, the password never expires, and that they have a mailbox.
Once the user has been created, find them in the list of users, right click on them, and goto Properties. Once the new window opens click on the tab marked "Member of". Add the postmaster to the "Administrators" group, but not the "Domain Administrators" group as this will stop access to the mailboxes.
The next task is starting setting some more permissions for the user. The first thing to do here is to open the Exchange System Manager (usually kept in the Microsoft Exchange folder of the start menu) and to find the group that the mailboxes belong to. In this example the name of the group is "First Administrative Group". Now, right click on the group and click "Delegate Control...".
Now you will see a setup wizard appear, click Next to start. On this screen (as shown above) click on Add, and then add the postmaster user as an Exchange View Only Administrator. Once done you will need to setup permissions on a per-folder basis for any public folders that you wish the postmaster to have access to. In this example I'm going to give it access to a users Free/Busy information so that the postmaster acts as a shared schedule of who's busy when. To access the special Free/Busy information, rigth click on "public folder" and then click "View System Folders". When expanding the public folders list you will now see a list of special folders, amongst these is one called "Schedule+ Free Busy". If you expand this you should see a folder named something along the lines of:
EX:/o=<Organisation>/ou=<Administrative Group>The ou value is likely to be set to "First Administrative Group". Right click on this folder, and goto properties. On the properties window click on the Permissions tab, and then the button labelled "Client permissions...". Add the postmaster to the list here with "Owner" permissions, then click "OK" to store the changes. Now click on the 3rd button labelled "Administrative rights..." and give the postmaster Full control.
Now you are ready to restart the Exchange service so that the permissions take effect.
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