I am sorry that was rather abrupt. When I double click on the attachment literally nothing happens, if I right click I get the menu as previously illustrated but again clicking on open does nothing.

Going back to this image you posted in the past.

That file type is given as image/HEIC. I missed that when I asked you o look. You also obviously did not look at the email that image was included in as the file type is not JPG as the file extension erroneously describes it. It is a HEIC file.

Now Apple have a lot to answer for, like Microsoft, they just have to pollute a world of standards based file formats with proprietary garbage they fail entirely to identify correctly.

Google AI has this to say about HEIC, I will quote it as I have very strong feelings about Apple and their inability to play in a sandpit with others.

HEIC, which stands for High Efficiency Image Container, is an image file format used on Apple devices, particularly iPhones and iPads. It's an updated version of the High Efficiency Image Format (HEIF) and is known for using advanced compression methods to achieve smaller file sizes with comparable or even better image quality than traditional formats like JPEG.

So go to the Microsoft store, search for HEIC and install one of the converters that suits your needs. I have HEIC+ installed, but I have only used it perhaps twice so really have no opinions as the what might or might not be good. Although I did give my correspondent that sent me Apple propriety formatted files to print a serve for being so inconsiderate.

So now I have this HEIC entry in my list of file associations in Thunderbird and I have little doubt you should have something exactly the same as this whole discussion is about HEIC not JPG.

Good call Matt. I had looked at the actual attachment which had the .jpg extension in the name which is obviously confusing the issue.

It would have been instantly noticable if the image still had the heic extention.

Thank you again. I will try the Heic, though i do not understand that I require a different viewer when Thunderbird can display the picture in the message but not open it separately. I can also open if I save and open with another programme.