bitZ_email.php, is now having the checks to support only .mp3, .wav, .m4a, .ogg formats, but yet not tested with audio conversion part.
converter.php, is in progress to get conversion module for m4a and wav audio files, yet not completed.
siteconfig.inc.php, just for testing on my local machine, DBUSER and DBPASS values are modified, should be modified back for client's test server.