Send emails with Python using SMTP over TLS

mail.py

import smtplib
import os
from email.message import EmailMessage

with smtplib.SMTP_SSL('mailserver.example', port=465) as smtp:
    smtp.login('my-user', 'my-secret-password')

    from_addr = 'my-user@mailserver.example'
    to_addr = 'anli@spreadshirt.net'
    msg = EmailMessage()
    msg.set_content('This is a test.')
    msg['Subject'] = 'A test subject'
    msg['From'] = from_addr
    msg['To'] = to_addr

    smtp.send_message(msg, from_addr, to_addr)