Attach voicemail to email issue

We have a problem when selecting the following under the extensions:

Attach voicemail to email

Once that option is selected, voicemails for that extension are being send to the email address specified, but the WAV file in the default-tenant/EXT directory is not in there.

The msg0000.txt is there, but not msg0000.WAV

This creates a major problem, when you then check the voicemail from the phone it will not delete or play it as the WAV file is not in the directory.
msg0000 does not exist in any format

---------SOME MORE INFO:-----------
If delete=yes is set, it will email and then delete the message from the server and everything works. (it will delete msg0000.txt and msg0000.WAV) and the Phone does not indicate that there is a message

If delete=no is set, it will email the message, then it deletes the WAV file, but keeps the .txt file in the Directory, The phone indicates there is a message in the box, but since the WAV file is gone it will not play or delete it and the MWI keeps on flashing.

If notify by email is check alone the message stays in the directory (txt and WAV) and it works fine
from the phone.
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Any help would be appreciated.

Thanks