I want to record a voicemail message for my Nextiva phone service using Sonar X3. They call out for a spec on the wave file and it is:
 
The only format accepted by the system is: .wav, PCM, Uncompressed/PCMU, 8000z, 8 or 16 bit MONO.
 
I am not sure what the PCMU part is all about. I noticed also that my sample rates available on X3 go from 44,000 to 88,200 so I don't know which one to select. Does anyone have any input on how I can match this format they request?

Thanks,
Sharkky

You would probably be better of exporting as a standard wave file as you normally do in Cakewalk.  Then use a standard audio converter like (Goldwave for instance) to convert the resultant wave file to a PCM, 8000z, 16 bit MONO file.

Cakewalk will allow whatever your interface can do. Try using the lowly built-in Windows sound chip and choose MME as the driver model...that will likely let you do 8 kHz.
 
"You've got mail"

I had the "You've got mail" mp3 for email notifications on my phone..... then not.
 
I just hold the phone up to the speaker to record Sonar created voice mail prompts.

I used SoundForge for this task, but I'd try Craig Anderton's method if you don't have an external application.
 
My interface could play back the low res file, so not sure why Sonar couldn't encode that low.