Resolution
These are three different ways to address messages over the phone:
Enter the extensions of the subscribers.
Spell the first names of the subscribers.
Spell the last names of the subscribers.
In order to address by name, a lettered keypad is required on the phones of the subscribers. This is where those settings can be changed. These are the available options to search by:
lastname/firstname
firstname/lastname
extension
Regardless which option is chosen, as subscribers address a message by phone, they can switch between name and extension with either of these key press combinations:
But, when the Enable Spelled Name Search check box is unchecked on the System > Configuration > Settings page, subscribers can only address messages over the phone with the subscriber extensions. Remember that this must be changed on all of the subscribers.
Refer to these documents for more information: