Master Python Email Automation: Send Text, HTML, Images, Attachments, and SSL Emails

File-based Email

Send a simple plain‑text email using

#!/usr/bin/env python3

#coding: utf-8

import smtplib

from email.mime.text import MIMEText

from email.header import Header

sender = '***'

receiver = '***'

subject = 'python email test'

smtpserver = 'smtp.163.com'

username = '***'

password = '***'

msg = MIMEText('你好', 'text', 'utf-8')  # Chinese needs utf‑8, single‑byte characters do not

msg['Subject'] = Header(subject, 'utf-8')

smtp = smtplib.SMTP()

smtp.connect('smtp.163.com')

smtp.login(username, password)

smtp.sendmail(sender, receiver, msg.as_string())

smtp.quit()

HTML Email

Send an HTML‑formatted email by creating a MIMEText object with the HTML payload.

#!/usr/bin/env python3

#coding: utf-8

import smtplib

from email.mime.text import MIMEText

sender = '***'

receiver = '***'

subject = 'python email test'

smtpserver = 'smtp.163.com'

username = '***'

password = '***'

msg = MIMEText('<h1>你好</h1>', 'html', 'utf-8')

msg['Subject'] = subject

smtp = smtplib.SMTP()

smtp.connect('smtp.163.com')

smtp.login(username, password)

smtp.sendmail(sender, receiver, msg.as_string())

smtp.quit()

Email with Embedded Image

Use MIMEMultipart('related') to combine HTML content and an image referenced by CID.

#!/usr/bin/env python3

#coding: utf-8

import smtplib

from email.mime.multipart import MIMEMultipart

from email.mime.text import MIMEText

from email.mime.image import MIMEImage

sender = '***'

receiver = '***'

subject = 'python email test'

smtpserver = 'smtp.163.com'

username = '***'

password = '***'

msgRoot = MIMEMultipart('related')

msgRoot['Subject'] = 'test message'

msgText = MIMEText('<b>Some <i>HTML</i> text</b> and an image.', 'html', 'utf-8')

msgRoot.attach(msgText)

fp = open('h:\python\1.jpg', 'rb')

msgImage = MIMEImage(fp.read())

fp.close()

msgImage.add_header('Content-ID', '')

msgRoot.attach(msgImage)

smtp = smtplib.SMTP()

smtp.connect('smtp.163.com')

smtp.login(username, password)

smtp.sendmail(sender, receiver, msgRoot.as_string())

smtp.quit()

Email with Attachment

Attach a file (e.g., an image) as a base64‑encoded part.

#!/usr/bin/env python3

#coding: utf-8

import smtplib

from email.mime.multipart import MIMEMultipart

from email.mime.text import MIMEText

from email.mime.image import MIMEImage

sender = '***'

receiver = '***'

subject = 'python email test'

smtpserver = 'smtp.163.com'

username = '***'

password = '***'

msgRoot = MIMEMultipart('related')

msgRoot['Subject'] = 'test message'

# attachment
att = MIMEText(open('h:\python\1.jpg', 'rb').read(), 'base64', 'utf-8')
att['Content-Type'] = 'application/octet-stream'
att['Content-Disposition'] = 'attachment; filename="1.jpg"'
msgRoot.attach(att)

smtp = smtplib.SMTP()

smtp.connect('smtp.163.com')

smtp.login(username, password)

smtp.sendmail(sender, receiver, msgRoot.as_string())

smtp.quit()

Group Email

Send the same message to multiple recipients by providing a list.

#!/usr/bin/env python3

#coding: utf-8

import smtplib

from email.mime.text import MIMEText

sender = '***'

receiver = ['***', '****', …]

subject = 'python email test'

smtpserver = 'smtp.163.com'

username = '***'

password = '***'

msg = MIMEText('你好', 'text', 'utf-8')
msg['Subject'] = subject

smtp = smtplib.SMTP()
smtp.connect('smtp.163.com')
smtp.login(username, password)
smtp.sendmail(sender, receiver, msg.as_string())
smtp.quit()

Email Containing All Elements

Combine plain text, HTML, images, and attachments in a single multipart message.

#!/usr/bin/env python3

#coding: utf-8

import smtplib

from email.mime.multipart import MIMEMultipart

from email.mime.text import MIMEText

from email.mime.image import MIMEImage

sender = '***'

receiver = '***'

subject = 'python email test'

smtpserver = 'smtp.163.com'

username = '***'

password = '***'

# create container
msg = MIMEMultipart('alternative')
msg['Subject'] = "Link"
text = "Hi!
How are you?
Here is the link you wanted:
http://www.python.org"
html = """\
Hi!<br/>
How are you?<br/>
Here is the <a href=\"http://www.python.org\">link</a> you wanted.
"""
part1 = MIMEText(text, 'plain')
part2 = MIMEText(html, 'html')
msg.attach(part1)
msg.attach(part2)
# attachment
att = MIMEText(open('h:\python\1.jpg', 'rb').read(), 'base64', 'utf-8')
att['Content-Type'] = 'application/octet-stream'
att['Content-Disposition'] = 'attachment; filename="1.jpg"'
msg.attach(att)
# send
smtp = smtplib.SMTP()
smtp.connect('smtp.163.com')
smtp.login(username, password)
smtp.sendmail(sender, receiver, msg.as_string())
smtp.quit()

SSL‑Secured Email

Use STARTTLS to encrypt the connection before sending the message.

#!/usr/bin/env python3

#coding: utf-8

import smtplib

from email.mime.text import MIMEText

from email.header import Header

sender = '***'

receiver = '***'

subject = 'python email test'

smtpserver = 'smtp.163.com'

username = '***'

password = '***'

msg = MIMEText('你好', 'text', 'utf-8')
msg['Subject'] = Header(subject, 'utf-8')
smtp = smtplib.SMTP()
smtp.connect('smtp.163.com')
smtp.ehlo()
smtp.starttls()
smtp.ehlo()
smtp.set_debuglevel(1)
smtp.login(username, password)
smtp.sendmail(sender, receiver, msg.as_string())
smtp.quit()