Following is a simple example Python script that can be used to send an email using smtplib, MIMEMultipart and MIMEText.

#!/usr/bin/python3
import smtplib
from smtplib import SMTPException
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText

host           = 'mail.example.com'
port           = 587
username       = 'xmailserviceaccount'
password       = 'itsasecret'
sender         = "No Reply <no-reply@example.com>"
recipients     = ["John Doe <john.doe@example.com>", "Jane Doe <jane.doe@example.com>"]
msg            = MIMEMultipart()
msg['From']    = sender
msg['To']      = ", ".join(recipients)
msg['Subject'] = "Example Subject"
message        = "Example <b>Message</b>"

msg.attach(MIMEText(message, 'html'))

try:
  server = smtplib.SMTP(host, port)
  server.ehlo()
  server.starttls()
  server.ehlo()
  server.login(username, password)
  server.sendmail(sender, recipients, msg.as_string())
  server.quit()
except SMTPException as exception:
  print f"sendmail raised the following exception: {exception}"
else:
  print "Email successfully sent"