I'm pretty sure you can do this with a Office365 & their automation stack Power Automate.

Obviously it's only an option if your org has already sunk deep into Microsoft-of-things (MoT) universe.

If you want the pdf to look anything like the email, you will need to render it in a browser and capture a pdf. It’s not particularly hard if you know what you’re doing.

Any libs to help with that? Thanks.

A headlees browser like e.g. puppeteer would do the job. I use it a lot for exatly that purpous...