It is easy to add a hyperlink to an Apple Mail message.
Select the text that you would like to be the ‘linking text’, and control-click on it.
In the pop-up window, scroll and select link.
On one occasion, when control-clicking in a message, I had another option ‘Import Image’ in the pop-up which allowed me to import an image directly from an attached device, such as my iPhone (or a scanner).
It worked beautifully, but I can’t replicate this now.
Anyone else found this?