Due to technical limitations, users on Entourage can only be given full access to the entire mailbox.

To grant full mailbox permissions, follow the steps in the following article:
How Do I Enable Sends As Or Full Access Permissions On Exchange Account?

Once a user has been given full mailbox access to the mailbox in question, that user will need to make the following changes in Entourage:

  1. Go to Tools > Accounts and click on Exchange tab on the right.
  2. Select your Exchange account, then click on Edit or double-click on the account name.
  3. Click on Delegate tab.
  4. Under 'Users I am a delegate for', click on Advanced.

  5. In the Advanced Settings window, fill in the following information:

    Name: Enter the display name of the delegate mailbox.
    E-Mail Address: Enter the user's address in the form [mailbox-username]@[accountusername].msoutlookonline.net
    Server Address: Enter the same server address you use to connect to your account in Entourage. You can find it on the Account Settings tab under Exchange server address. You will need to substitute your email address with the email address of the user you are a delegate for.
    Requires a secure connection (uses SSL): Select this option.

  6. Click on Ok and return to the main screen. The mailbox will appear in the left pane menu.