Why doesn't my voicemail-to-email mp3 file play?

On occasion, you may find that an mp3 file, sent to you as the voicmail-to-email attachment, cannot be played.  An error similar to the image below will be seen:

"This file isn't playable.  That might be because the file type is unsupported, the file extension is incorrect, or the file is corrupt"

The most common cause of this is because the length of the voicemail message itself was very close to zero seconds long, and so the file is empty.  Please check the length of the voicemail message in the Corvum portal to see if the length is 00:00 - if it is, you can disregard this message.

Our phone system ignores all voicemail that is less than 3 seconds long (these are discarded), but on occasion a voicemail message is just long enough to be considered 'legitimate', yet is still not long enough to actually create a valid file.