Thanks, dwayneg- your suggestion helped us determine the issue is probably with our 3rd-party mail solution (Kerio), as all other methods of viewing VM messages from the Mitel system show the attachment as a WAV file (pure IMAP, webmail, etc.). Kerio provides an extension that snaps into Outlook. Per their support team, Mitel's failure to populate a field in the voice message inhibits their extension from determining the correct attachment file name, namely> Content-Disposition: voice-message; attachment; filename="". As far as we know, they are the only ones looking here for the file name. It appears other email clients are looking here> Content-Type: audio/x-wav; name="vm Fri Mar 20, 2015 08:22 AM.wav". This information is visible when viewing the source of an email. So I guess we're screwed unless someone knows how we can train the Mitel system to populate the filename portion of the Content-Disposition field.
