question

Mr. Green,

The "canned" responses of the Auto Attendant will not enumerate all your extensions. You must do that yourself. You have to record a custom announcement and include all the extensions you want to be available to a calling party. If you want to add other information to your "Welcome" announcement you would do that also, such as "Welcome to the XYZ Company, your home for custom widget sales and service. Please listen carefully as our options have changed. If you know your party's extension, you may enter it at any time."

Then you can add the listing of your extensions. If you are using the single level IVR (Auto Attendant) you might record something like this:
For Sales, Press 1
For Customer Support, Press 2
For Billing and Accounting, Press 3
etc.

If you are using the multi-level IVR (Auto Attendant) you have to record a custom announcement for each sub-level. For example,
For Sales, Press 1
     For Widget Sales, Press 1
     For Doo-Dad Sales, Press 2
     For Other Sales, Press 3

For Customer Support, Press 2
     For Installation Support, Press 1
     For Return Information, Press 2

For Billing and Accounting, Press 3
     For a copy of your current invoice, Press 1
     To pay your bill, Press 2
     To close your account, Press 3

I hope this makes sense to you. If you would like more information on the auto attendant, you can start here: http://www.ringcentral.com/office/features/auto-attendant/overview.html

Mr. Green.  Jan is correct.  Also if you are a new customer, your Implementations Advisor will go through all this with you to explain in detail.  If you don't know who that is, contact your sales rep.