Would like to use Unavailable Message instead of Busy when on DND

Does anyone know how to make the Unavailable Message play when someone is leaving a voicemail and the Asterisk DND (*76) is enabled for the extension? It appears that the FreePBX system is playing the Busy message instead. I appreciate anyone’s input!

It would be really great if this were configurable in FreePBX. FreePBX always considers DND as busy, and then plays a busy dialtone (if no voicemail) or a busy voicemail message if voicemail is enabled.

This was also asked about here in 2008 and 2011: DND Voicemail Behavior

But there seems to be no solution. I noticed this today when I wanted to switch from phone-managed DND (where my Snom phones return unavailable) to server-managed DND (where freepbx returns busy).

Since we’re using DND if the user is not present or does not want to be disturbed for longer times (and no voicemail is enabled), busy is really not good. This could lead to callers thinking that the user is on the phone and that they must try again later - even though they probably have no chance at all since the phone is most likely to remain in DND for hours or days.