It depends on how the entry prompt is programmed for the Caller App built bulletin board. If it is set as Announcement then you would logon to the mailbox and record an announcement (remember not a greeting, but an announcement...Aria TUI press 4 then 5, Audix TUI 5 then 2, Serenade TUI 1 then 6).
If it is set as Application prompt you would use the Caller Apps editor to record the script or import a WAV file.
Chuck
RCT Technologies