Yeah - certainly JT3. I am new to Calibre as well, and the only reason I was able to get as far as I did is the awesome 'getting started' page here:
https://manual.calibre-ebook.com/dev...tting-the-code
I happened to be on my Windows computer, so I followed the steps in the "Windows development environment", and was up and running in just a minute or two (I mistyped the environment variable the first time and it threw a nice, verbose error.)
Since Kovid has included the ability to allow a normal install of Calibre to use the source directory directly, I didn't even need to worry about compiling or python version or anything. It just worked. (starting with hello world example!)
Assuming you aren't asking about implementation details - (which was just basically digging around all the Python functions in the code with the string "email") - that was all it took. If you want to apply the patch to your own installation, follow those same instructions in the link, but then take that hack_in_auto_email.txt file, and apply it to that directory using 'git apply' (
https://git-scm.com/docs/git-apply).
I would love to get this pushed to the github, so will try to circle back to it in a while. Hope this helped!