Thanks. I would really like mod_voicemail to be database driven, instead of by XML and cURL.
I noticed in the documentation that you can provide an ODBC handle in the voicemail.conf.xml file, and so I tried it with MySQL.
It created the two tables, voicemail_msgs and voicemail_prefs properly, and voicemail_msgs works the way I expect; when a new voicemail is created it writes a new record in this table.  But I don't understand the purpose of voicemail_prefs;  when I add a record here with a username and password, mod_voicemail ignores it. So I still have to use the config file or xml_curl to set-up the users. It doesn't seem like mod_voicemail reads from or writes to this table.