Location of where voicemail messages are stored in asterisk voip system

By default, Asterisk will store voice messages in the spool folder, at /var/spool/asterisk/voicemail/<context>/<mailbox>

You many note there are .WAV and .wav files of the same name e.g. unavail.wav and unavail.WAV with the .WAV file being larger – about 10 times the size. These are different quality of recordings.

Here