Attachment in non-multipart email will not be attached to the request created

Problem Statement

Emails with content-type other than Multipart will be created as a new request, however if the email contains an attachment it will not be added to the request

Steps to Reproduce the Problem

1. Send an email to Service Desk project with content-type below. For example, the voicemail notification through email from Cisco Unity Connection

    Content-Type: audio/wav; name=VoiceMessage.wav
    Content-Transfer-Encoding: Base64
    Content-Disposition: inline; filename=VoiceMessage.wav; voice=Voice-Message
    

2. The request will be created without the .wav file attached.

Cause

The mail handler has not been designed to handle non-multipart email properly.

Workaround

Try forwarding the email, a request will be created with the .wav file added as an attachment in the comment.
The forwarded email will have Content-Type: multipart/mixed or Content-Type: multipart/alternative in the email header