Use this dialog box to create an Exchange Mailbox client. Use the Service Account Settings tab to enter the service account information for the Exchange Mailbox client. The information that you enter depends on which environment type you selected.
Exchange Service Account
The list of service accounts that have been associated with the Exchange Mailbox client.
Add
Clicking Add opens the Exchange Service Account Credentials dialog box.
Configure service accounts later
Select the check box if you want to configure the service accounts after you create the Exchange Mailbox client.
When you add the service account later, clear the Configure service accounts later check box to make the Add button available.