I want to be able to send gmail messages from a raspberry pi, ideally from a single line of a shell script - I know I can use a mail server other than gmail that supports less secure login options, or go to https://www.google.com/settings/security/lesssecureapps and change the settings there - that is NOT what I want to do, as I would prefer to use the newer version of OAUTH
There seem to be many e-mail options, most with more features than what I care about, but I don't see OAUTH support as an "advertised" feature (note: I don't want to receive e-mails or check them, nor do I care for a GUI) - what is the simplest way to achieve this?
I would prefer free and open source, and also relatively easy to setup/configure, in that order as far as priorities go.