Currently the built-in voice mail mechanism is somewhat basic and there isn't really much you can do to add features to it if that is what your asking. I.e. I don't believe you can add any menu options to the 'checking voice mail' menu. I think the system needs a bit of a makeover, and frankly considering IVM is designed to be pretty much an advanced voice mail system, I find it hard to believe that it lacks many features and contains a couple of bugs (see below).
For instance, when accessing voice mail by phone:
- The date and time is only said if the message is from "Today" or "Yesterday" because the system is not able to say the months or week days
- If the time of the message is something like 4:09 PM, it is announced as "four nine PM"
- There isn't an option to announce the caller-id for messages
- There is no option to skip a message
- If the messages are old, there is no introduction to the message at all when calling to check.. the first message just starts right away, a bit unexpectedly
- There is no separation between new and old messages (i.e. ones you have listened to/saved)
It does have the mailbox setup menu (dial 8 I think) which provides the necessary functionality to record away messages and set passwords and what not. But that is pretty much how the voice mail system operates, and you can't really alter it.
If you're looking into a more advanced VM system, you will need to program your own one using several OGMs and the various record actions available.