send email (text and html) using python

smtp_send_email.py

#!/usr/bin/env python3

import sys
import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
import dns.resolver


msg = MIMEMultipart('alternative')
plain_part = MIMEText('testing plaintext 123', 'plain')
html_part = MIMEText('<h1>Test</h1><p>this is a test email</p>', 'html')


msg.attach(html_part)
msg.attach(plain_part)


if len(sys.argv) < 3:
    print("Usage: <server|auto> <sender> <recipient> [recipient 2] [recipient 3] .. ")
    exit(1)

server = sys.argv[1]
    

# me == the sender's email address
# you == the recipient's email address
msg['Subject'] = 'Test email'
sender = sys.argv[2]
msg['From'] = sys.argv[2]
recipients = sys.argv[3:]
msg['To'] = ','.join(recipients)

if server == 'auto':
    # use the first recipient to figure out mail server
    domain = recipients[0].split('@')[1]
    for x in dns.resolver.resolve(domain, 'MX'):
        server = x.to_text().split('\n')[0].split(' ')[1] # get first domain
        
print("sending using server:", server)
# exit()


# Send the message via our own SMTP server, but don't include the
# envelope header.
s = smtplib.SMTP(server)
response = s.sendmail(sender, recipients, msg.as_string())
print("response:", response)
s.quit()