Sending email with the Python standard library

send_email.py

import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText

# sender details
sender = 'alias@domain.org'
recipients = ['alias@domain.org', 'email2@domain.com', '3rdrecipients@outloo.com', ]

# create a MIME obj
msg = MIMEMultipart()
msg['From'] = sender
msg['To'] = ', '.join(recipients)
msg['Subject'] = 'Message Subject'
body = MIMEText('This is the body of the email message...')
msg.attach(body)

# format the message
text = msg.as_string()

# authentication
auth_user = 'alias@domain.org'


def prompt(prompt):
    return input(prompt).strip()


def send_email():
    try:
        s = smtplib.SMTP('smtp.gmail.com', 587)
        s.set_debuglevel(0)
        s.connect('smtp.gmail.com', 587)
        s.ehlo()
        s.starttls()
        s.ehlo()

        try:
            s.login(auth_user, prompt('Enter Password:\n'))
            print('SMTP Login successful')

            try:
                s.sendmail(sender, recipients, text)
                s.quit()
                print('Mail sent to {} successfully...'.format(str(recipients)))

            except smtplib.SMTPRecipientsRefused as send_err:
                print('Email recipients refused by the server: {}'.format(str(send_err)))

        except smtplib.SMTPAuthenticationError as auth_err:
            print('SMTP Authentication Error; {}'.format(str(auth_err)))

    except smtplib.SMTPConnectError as smtp_err:
        print('The server responded with an error: {}'.format(str(smtp_err)))


# call the function
send_email()