Any embedded RFC822 attachment is shown as EML attachment. In an Android environment just a button will be shown which leads to an external app … (not handled by K9, alas, I can’t control the set of apps). Wouldn’t it be nice, if K9 opens and handles such object by itself? Especially to inspect the header of such mails. K9 has definitely all the abilities to do so. I’d expect that could be easily intergrated and implemented … could this be taken to the whishlist?