[asterisk-users] Need good voicemail documentation

[Jaap Winius]

Hi list,

After wrestling with the voicemail system for a while (Asterisk  
1.4.14, Debian etch), I got it to work, but I still have lots of  
questions, like:

     * Why can't I delete any voicemail messages?
       (Response: "Message undeleted.")
     * Why can't I listen to the messages in the Old folder?
     * Why can't I use the advanced options?
       (Response: "I'm sorry, I did not understand your response.")
     * How come if I put "mailbox=1000 at rjs_voicemail" in my phone's
       context of sip.conf, do I get an error?
       (CLI: "...Remote host can't match request NOTIFY to call...")

Unfortunately, none of the books and other documentation I've found on  
the subject goes into enough detail to provide answers to such  
questions. So, can anyone recommend some good Asterisk voicemail  
documentation that goes beyond merely scratching the surface?

Cheers,

Jaap