Did you really think it was going to be that easy?
You have to program the VS in the proper hunt group (7) to make it work. For example, if you put it in the 2nd slot, because it was only a 2-slot carrier, it would become extensions 22 and 23 on a 2-port license and 20-23 on a 4-port. The Partner Mail is installed to the right of any 206 or 400 cards, so that you don't have any holes in the extension numbering plan.
Here's a manual for the VS R4. It should work for your system for the basic installation. http://public.carl.airpost.net/Avaya/Partner%20Mail%20VS%20R4%20Installation%20and%20Programming.pdf
Page 35 is your installation information and page 50 tells you how to program the ACS.