Populate email programatically with a From field in a POP3 server

I have a POP3 email account (Outlook) and I am able to retrieve emails from it programatically using poplib library (NodeJS).

Now I would like to populate emails in the server programatically: generating a new email where I can specify the "From", "To", "Subject", etc. And making it available in this POP3 account. I don't mean sending an email to that account, but generating an email as if it had been received in that account.

How can I do that? I am open to use any programming language / library.

via Arturo