There are two methods to access a shared departmental account and both assume that you have full mailbox rights to the departmental account:
To access the full Mailbox (including subfolders--Deleted, Sent, etc.)
Follow the same configuration procedure for setting up your primary Hawkmail account. Repeat the process for each departmental account you need to access. (NOTE: you will need a password for this option)
To access just the Calendar, Inbox, and Address Book
With Entourage SP2 choose File | Open Other Users Folder. Enter the departmental account in the 'User' field and select the type of folder you want to access (e.g., Calendar, Inbox, Address Book) in the 'Type' field. Click OK. The shared folder will appear in the folder view underneath your Hawkmail account.
If you want to send a new message from a shared departmental account, change the From field in your new message to the departmental account name by selecting it from the drop-down arrow.