I have the same issue with TheBat Voyager 10.2 and 10.3 and earlier version too (win7), that in some email images are not displayed correctly. Visible is only the pixelized square in dark colors On my investigation: images are not visible on emails which source is base64. But looking for another mail app I found that https://www.foxmail.com/win/en/ uses too https://github.com/salvadordf/CEF4Delphi/releases library and on them, on this email on which images are not visible in TheBat are visible on Foxmail, so... something must be wrong on decoding base64 content and trying to "download" images from this decoded code.
I think, that my post will be helpful to fix this issue.
I would never have thought to look there. Great work! It does make sense now, but you'd expect Windows to throw up an error when it can't connect to a server because the encryption method isn't supported. 9apps cartoon hd