Voicemail files: .WAV vs .wav

Hi forum,

I'm running into a problem with voicemail-to-email. Currently Trixbox sends out the .WAV file as an email attachment. This is causing problems with blackberry devices, they are not able to play the .WAV file because the file extension is uppercase. I've verified this by taking the emailed WAV file, renaming it to .wav, and re-forwarding the email, and everything works fine.

I understand that there are two WAV files (lowercase and uppercase) what use different encoding schemes. I would like to continue to send the .WAV file (uppercase) in the email notification because of the smaller file size, but I'd like to have the email attachment filename converted to lowercase.

What's the simplest way to do this? Any suggestions?

Thanks in advance...