python でメールの受信

Python3 で、imap サーバーからメールを受信する方法です。
Yahoo Mail で確認しました。

imap_get.py

#! /usr/bin/python
#
#   imap_get.py
#
#					   Jun/26/2023
#
# --------------------------------------------------------------------
import os
import sys
import ssl
import imaplib
import email
from email.header import decode_header, make_header
from dotenv import load_dotenv
# --------------------------------------------------------------------
sys.stderr.write("*** 開始 ***\n")
#
dotenv_path = '.env'
load_dotenv(dotenv_path)
#
server= os.environ.get("SERVER")
usr= os.environ.get("USR")
password= os.environ.get("PASSWORD")
try:
	context = ssl.create_default_context()
#	context = ssl._create_unverified_context()
	imapclient = imaplib.IMAP4_SSL(server, 993, ssl_context=context)
#   sys.stderr.write("*** usr = %s ***\n" % usr)
#   sys.stderr.write("*** password = %s ***\n" % password)
	imapclient.login(usr,password)
	imapclient.select()
	typ, data = imapclient.search(None, 'ALL')
	icount = 0
	for num in data[0].split():
		typ, data = imapclient.fetch(num, '(RFC822)')
		email_message = email.message_from_bytes(data[0][1])
#
		email_from = str(make_header(decode_header(email_message['From'])))
		print(email_from)
		subject = str(make_header(decode_header(email_message['Subject'])))
		print(subject)
		sys.stderr.write(subject + "\n")
		

#		msg_encoding = 'iso-2022-jp'
		msg_encoding = 'utf-8'

		if email_message.is_multipart() == False: # シングルパート
			sys.stderr.write("*** eeee ***\n")
			byt  = bytearray(email_message.get_payload(), msg_encoding)
			body = byt.decode(encoding=msg_encoding)
		else:   # マルチパート
			sys.stderr.write("*** multi part ***\n")
			prt  = email_message.get_payload()[0]
			byt  = prt.get_payload(decode=True)
			try:
#				body = byt.decode(encoding=msg_encoding)
				body = byt.decode("utf-8")
			except Exception as ee:
				sys.stderr.write("*** error *** byt.decode\n")
				sys.stderr.write(str(ee) + '\n')
			sys.stderr.write("*** hhhh ***\n")
#
		print(body)
#
		icount += 1
		if (2 < icount):
			break
	imapclient.close()
	imapclient.logout()
except Exception as ee:
	sys.stderr.write("*** error ***\n")
	sys.stderr.write(str(ee) + '\n')

sys.stderr.write("*** 終了 ***\n")
# --------------------------------------------------------------------

.env

SERVER = 'imap.mail.yahoo.co.jp'
USR = '*****@yahoo.co.jp'
PASSWORD = '*********'

確認したバージョン

$ python --version
Python 3.11.3

Yahoo 以外のサイトで、次のようなエラーが出る時の対策

[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: Hostname mismatch, certificate is not valid for

#       context = ssl.create_default_context()
       context = ssl._create_unverified_context()