It is perfectly normal to show inline images as attachments, because well, they are! They are still attachments, just convereted into uuencode and embedded into the body of the message, like MHT archives. When you view as HTML, they show as either images, attachments, or both. When you view as text, they must always show as attachments, since a text only view cannot display any images. But they ARE in fact attachments, no matter how they are handled. You can embed ANY filetype as in-line, that is how newsreaders work!
Very old modems, used to send ALL THE DATA as uuencode, even large binaries downloaded from a website. BBS boards did the same. some of the first viriuses were embedded this way. You can even embed one mine type, inside another this way. In fact, that is how old MS Office embeded images inside documents. Another method is OLE, but OLE does not work very will across domains, as it requires an "image server" CLSID and the software to be present on both the sending and receiving system, and the files in the same relative path locations. But it is still used on some software.
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