Gmail with Python

Getting into Gmail with Python.

Use a testing account.

Simple way: (the way 3rd party clients like Thunderbird do it.)

• SMTP (comms between servers) smtplib is builtin
• POP3 (read only from email server) poplib is builtin
• IMAP (read/write with email server) imaplib is builtin
  • email python library/parser

Complex way: Gmail API with Google Cloud (good luck)

Warning: Don't hardcode tokens and keys. (how to handle secrets)

Config:

• List of Servers/Subdomains for Major Email Providers (imap.gmail.com)
• username/email youremail@example.com
• password: Special "App Password"
  • You will need to click around in your account

IMAP

import os
from dotenv import load_dotenv
load_dotenv('.env')
username = os.getenv('USERNAME')
password = os.getenv('PASSWORD')

import imaplib

server = 'imap.gmail.com'
imap = imaplib.IMAP4_SSL(server)
imap.login(email, password)

print(imap.list()) # lists mailboxes
status, messages = imap.select(mailbox="INBOX",readonly=True)

Emails on the server are assinged sequential IDs. Starting from 1.

msg_uid = 10
status, msg = imap.fetch(str(msg_uid),'(RFC822)') # no clue why RFC822
# msg
#  0: msg itself
#  1: (uid, data)

import email
data = msg[1][1]
m = email.message_from_bytes(data)

print(m.get_payload())

Glossary

NOOP command (imap.noop()) is a test packet. Similar to a ping.

MIME is Multipurpose Internet Mail Extensions

Header Fields

['Delivered-To', 'Received', 'X-Received', 'ARC-Seal', 'ARC-Message-Signature', 'ARC-Authentication-Results', 'Return-Path', 'Received', 'Received-SPF', 'Authentication-Results', 'DKIM-Signature', 'X-Google-DKIM-Signature', 'X-Gm-Message-State', 'X-Google-Smtp-Source', 'MIME-Version', 'X-Received', 'Date', 'X-Account-Notification-Type', 'Feedback-ID', 'X-Notifications', 'X-Notifications-Bounce-Info', 'Message-ID', 'Subject', 'From', 'To', 'Content-Type']

Dealing with Multipart Emails

Content-Type: multipart/alternative, mutlipart/mixed, etc.

Multipart Emails contain multiple parts with different types. And many email providers/clients don't bother minimizing the type, just always use the universal multipart.

.is_multipart()

Iterator: Warning! first object is parent itself!

• .walk() generator object to iteratre through all message parts.

"part" object:

• .get_content_type() (get subtype)
• .is_multipart() (can be nested)

Attachments

Actions

FLAGS:

• Marking Read/Unread