I could not find a command line program that would send multiple emails with one call, so I am making this one to serve that purpose.
I have been using msmtp to send emails, but each call to that command requires establishing a new SMTP socket, taking almost a second per email.
The goal of this program is to open an SMTP session once and use it to send a bunch of emails. I'm not sure how I'll do it yet, but one possibility is to have it repeatedly call an external command that submits individual emails to the established socket. We'll see.
As I investigate the SMTP process, I will save links to resources that help me understand it. These links are compiled on the Resources Page.