It seems that some scammers are trying to prevent their emails from showing up in the search engines, by encoding the messages into graphics images, such as .jpg files.
While researching a scam, with the help of an Administrator, I was introduced to a free online image to text converter, a type of web optical character recognition tool. It resides at http://www.newocr.com/ and the documentation says:
(With many thanks to Garreg Ddu for technical assistance )NewOCR.com is a free online OCR (Optical Character Recognition) service. NewOCR.com can analyze the text in any image file that you upload, and then convert the text from the image into text that you can easily edit on your computer.
Unlimited uploads, no registration, layout analysis (multi-column text recognition), 29 languages support, image files (JPEG, PNG, GIF, BMP, multipage TIFF) up to 5 MB, multipage PDF documents up to 20 MB