Thanks Brandon, I enabled this through CCA and it still didn't work. After reading the second link "configure integrated messaging" I ultimately had to specify a group that would access integrated messaging and assign a subscriber to the group. I thought that I did this in CCA however, it never worked. I've configured this UC500 by using the CCA and the command line so I don't know if that has something to do with it not working when I enabled it in CCA.
I had the same problem when I enable the vpn client. I had to allow ISAKMP UDP port 500, since I had cleaned up the outside interface and used extended ACL's some how the scipt in the VPN Client for CCA wouldn't write this ACL and apply it to the outside interface.
Thanks again for your help!!
Dan