import smtplib
from email import message_from_string

def initialize():
    _smtp_conn = None

    try:
        _smtp_conn = _connect_to_server()
    except Exception as e:
        print(e)

    print("SMTP Connection established successfully")
    print(_send_rawemail(_smtp_conn))

def _connect_to_server():

    _smtp_conn = None
    server = "smtp.gmail.com"

    # default the ssl config to non SSL i.e. either None or StartTLS
    func_to_use = getattr(smtplib, 'SMTP')

    # Get the SSL config to use
    ssl_config = "StartTLS"
    port = "587"
    _smtp_conn = func_to_use(server, port)
    _smtp_conn.ehlo()

    # Use the StartTLS command if the config was set to StartTLS
    if (_smtp_conn.has_extn('STARTTLS') and (ssl_config == "StartTLS")):
        _smtp_conn.starttls()

    _smtp_conn.ehlo()

    # Provide 'username' and 'password' for a valid email address
    # which is configured as per the SMTP protocol
    # For security reasons, I have not provided the valid credentials.
    password = "password"
    username = "user@domain.com"
    if password and username:
        if _smtp_conn.has_extn('AUTH'):
            _smtp_conn.login(username, password)

    return _smtp_conn

def _send_rawemail(_smtp_conn):

    raw_email = """To: testmail@gmail.com
From:user@domain.com
Subject:body with Unicodes

This is email body with Unicodes漢字.
"""
    msg = message_from_string(raw_email)
    email_from = msg.get('from', '')

    if not len(email_from):
        return "Failed to send the email. Sender not found"
    
    # In case the user provides 'CC' or 'BCC' but does not provide 'To'
    if not len(msg['to']):
        return "Failed to send the email. Receiver not found"

    email_to = [x.strip() for x in msg['to'].split(",")]
    if msg['cc']:
        email_to.extend([x.strip() for x in msg['cc'].split(",")])
    if msg['bcc']:
        email_to.extend([x.strip() for x in msg['bcc'].split(",")])
    email_to = list(filter(None, email_to))

    try:
        _smtp_conn.sendmail(email_from, email_to, msg.as_string())

    except Exception as e:
        print("An exception occurred.")
        return "{0} {1}".format(type(e).__name__, str(e))

    return "Message sent successfully."

if __name__ == "__main__":
    initialize()