How to send email using simple SMTP commands via Gmail?

For educational purposes, I need to send an email through an SMTP server, using SMTP's fundamental and simple rules.

I was able to do that using smtp4dev. I telnet localhost 25 and and commands are:

I want to do the same thing, using Gmail SMTP server. However, it requires authentication and TLS. I can't figure out how to do that for Gmail. Here's a screenshot of telnet smtp.gmail.com 587:

I searched and found many links including Wikipedia's article about STARTTLS command. But I'm not able to use TLS and authenticate to Gmail's SMTP server using command line (or sending commands myself in programming languages). Can anyone help?