Even when the vocal message is in attachment, templates used are "voicemail_notification.fr.html", "voicemail_notification.fr.body" and "voicemail_notification.fr.subject".
That's not the good ones.
It should be the "voicemail_notification_with_attachment.fr.html", "voicemail_notification_with_attachment.fr.body" and "voicemail_notification_with_attachment.fr.subject".
Even when the vocal message is in attachment, templates used are "voicemail_notification.fr.html", "voicemail_notification.fr.body" and "voicemail_notification.fr.subject". That's not the good ones. It should be the "voicemail_notification_with_attachment.fr.html", "voicemail_notification_with_attachment.fr.body" and "voicemail_notification_with_attachment.fr.subject".