From what I see there is not a CAB, you just need to add some entries in your registry to make it work:
Code:
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Today\Items\"Voicemail"]
"Enabled"=dword:00000001
"Order"=dword:00000003
"Type"=dword:00000004
"Options"=dword:00000000
"Selectability"=dword:00000002
"DLL"="\\Windows\\SPCSPlugin_Voicemail.dll"
"Flags"=dword:00000000