decode base64 with python give error

[thailq]

Oke I will post all my code here, can you check it for me, please.

import imaplib
import base64
import chardet
import quopri
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
mail_st = "[email protected]"
pass_st = "password"
imap = imaplib.IMAP4_SSL("mail.eplatform.vn",993)
imap.login(mail_st,pass_st)
        #quét mail
imap.select("INBOX")

status, response = imap.search(None,'(UNSEEN)')
unread_msg_nums = response[0].split()

        #in tổng mail chưa đọc
print(len(unread_msg_nums))

        #bắt đầu đọc mail
for e_id in unread_msg_nums:

    _, response = imap.fetch(e_id, '(RFC822)')
    print('bắt đầu in mail')
    content_email = str(response[0][1])
    print (content_email)
    str1 = 'Content-Transfer-Encoding: base64'
    str2 = 'Content-Transfer-Encoding: quoted-printable'
    str3 = 'Content-Transfer-Encoding: 8bit'

            #chia câu lệnh if để chạy mail

    if str1 in content_email:
        print('test thử coi sao')
        aaa= '5paw44GX44GE54mp5Lu244GM55m76Yyy44GV44KM44G+44GX44Gf44Gu44Gn44CB44GU56K66KqN\r\n44GP44Gg44GV44GE44CCCQ0KCQ0K5Y+X5LuY5pel77yaMjAxOOW5tDA55pyIMjDml6UJDQrlvpfm\r\nhI/lhYjlkI3vvJrjg4/jgqbjgrnjg4bjgq/jg47moKrlvI/kvJrnpL4gLQkNCuaLheW9k+iAhe+8\r\nmiBpbWFuaXNoaQkNCueoruWIpTog5qeL6YCgQ0FE5YWl5YqbCQ0K54mp5Lu2IDEg5Lu2CQ0KDQoJ\r\n54mp5Lu244Kz44O844OJ77yaMTAwMDAwNTANCgnnianku7blkI3vvJrlpKfkuYXkv53kuK0xMeWP\r\ntw0KCeeZuuazqOWFg++8mumWouilv+ODm+ODvOODoA0KCeeZuuazqOWGheWuue+8muioguatow0K\r\nCeW4jOacm+e0jeacn++8mjIwMTgtMDktMjEgQU0NCg0K6YCj57Wh5qyE77yaDQo='
 
        data1 = base64.b64decode(aaa)
        print(data1)

        begin_encoding = content_email.find('Content-Transfer-Encoding: base64') + 41
        retun_begin = content_email[begin_encoding:-1]
        end_encoding = (retun_begin.find('Content-Type')) - 38
        retun_end = retun_begin[0:end_encoding]
        print('bắt đầu base64')
        print (type(retun_end))
        print(retun_end)
        if retun_end:
            data = base64.b64decode(retun_end)
            print(data)

You can change email and pw of your, and send some mail in japanese language to this mail. I suggest sending mail by Gmail, remember that my problem is about decode to Japanese language

---

You can get this content to test just like my code ( sending by Gmail to this mail in your code )

新しい物件が登録されましたので、ご確認ください。	
	
受付日：2018年09月20日	
得意先名：ハウステクノ株式会社 -	
担当者： imanishi	
種別: 構造CAD入力	
物件 1 件	

	物件コード：10000050
	物件名：大久保中11号
	発注元：関西ホーム
	発注内容：訂正
	希望納期：2018-09-21 AM

連絡欄：