Access Hidden Library Menu Option On Mac. Follow the steps below to access the Hidden Library Menu option on your Mac. Left-click your mouse anywhere on the screen of your Mac. This will reveal the Go Option in the top menu bar of your Mac. You can also click on the Finder Icon in the Dock of your Mac to activate the Go Option. You can't remove: The GAL named Default Offline Address Book, which is the built-in GAL that's available in Exchange Online, and the only GAL that has the IsDefaultGlobalAddressList property value True. A GAL that's defined in an offline address book (OAB). For OAB procedures, see Offline address book.

Contacts User Guide

You can delete contacts and groups at any time.

In the Contacts app on your Mac, do any of the following:

• Delete a contact: Select a contact, then press the Delete key.

  If you select a contact who belongs to a group, click Delete in the message that appears.

• Delete a group: Select a group in the sidebar, then press the Delete key.

  If a group is used in a Smart Group (by including a condition that uses “Card is member of” or “Card is not member of”), you can’t delete the group until you change the condition or delete the Smart Group.

You can’t delete contacts in read-only accounts such as Google and Yahoo; you must delete the contacts directly in Google or Yahoo, for example. If you don’t want to see contacts from a specific account, stop using the account in Contacts. To do so, choose Contacts > Accounts, select the account, then deselect its Contacts checkbox.

If you stop using or remove an account, any edited contacts remain in your default contacts account.

Depends upon what you are trying to delete.You cannot delete default address books:'Personal Address Book'Collected Addresses'

If you try to delete them, then a new one will auto appear.If you add email addresses to address book by clicking on the FROM or TO header email address and select 'Add to Address Book', it will auto add to the 'Personal Address Book'.

'All Address Books' is not a true address book, it is like a search folder with the ability to display everything. You cannot delete 'All Address Books'.

You can stop outgoing email addresses going to the 'Collected Addresses'.You can switch it off so no outgoing email addresses are collected or choose another address book.Tools > Options > Composition > Addressing tabTo Stop all collecting:uncheck : 'Automatically add outgoing email addresses to my'

To select another address book for collecting:select: Automatically add outgoing email addresses to my'and select another address book from the drop down list.

Mac Address Book App

click on OK

Delete Contact Mac Address Book

Otherwise to delete any address book or Mailing List you have created:Select the address book in the left Directory Paneclick on 'Delete' OR right click on address book and select 'Delete'.