Transformer for application/octet-stream

Hello guys!

I want to achieve my goal, transform a .msg (Outlook Email).
So I want to create a rendition for the mail body at least.

ContentTransformer transformer = contentService.getTransformer(actualMimetype, MimetypeMap.MIMETYPE_PDF);if(transformer ==null){
    LOG.warn("no transformer found to transform from "+ actualMimetype +" to application/pdf");}else{
    render = renditionService.render(destNodeRef, QName.createQName(NamespaceService.CONTENT_MODEL_1_0_URI,"pdf"));}

The problem is, I can't transform a 'application/octet-stream' due to documentation:

"application/octet-stream and application/oda - bin, oda These formats cannot be transformed into, or generated from, any other format."

Does anyone has a solution to create a rendition for a 'application/octet-stream' file ? Or can I change the file into a other mimetype?