@sgunhouse JPEG files can be opened without downloading them when
the IE browser is used on a colleague's Windows laptop, so it is not the
OWA system which is insisting on only downloading JPEG files.
On another point, Opera also appears not to allow copying of a weblink using right click.... Nothing happens, when it should copy the weblink so it can be used elsewhere.
I have seen https://addons.opera.com/en-gb/extensions/details/open-with-application/ by michsens and wonder if that could help with
opening JPEG files (this addon may need extending to include JPEG files).