I can't seem to find a guide or reference on how to configure the 'indicator-applet' (aka MessagingMenu) that came about in the 9.04 release of Ubuntu. It's that little mail icon that lists messaging apps.
I can find docs about what it should do, people complaining about how it works, references that the API changed in 9.10, but not much on how to change the configuration.
The MessagingMenu design spec page says that the config file should be at
$HOME/.config/indicators/messages/applications/, but there's nothing there on my install (9.10).