So you can create a text file and the app will convert it to a voice file and send it out?You could do that using the Festival text-to-speech option, but IMHO it sounds a bit robotic:
http://festvox.org/voicedemos.html . Cepstral sounds better- visit
http://www.cepstral.com/demos/ to try it out. They'll sting you a couple of thousand $ if you want 64 ports operating at once though if it's the same message I suppose you could write a script to create a result you can send repeatedly. The alternative is to dial a specified number and record the message you want sent, after which you can send it off with voicemail blaster.
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1
