Description

assignee = None
closed_at = None
created_at = <Date 2020-02-26.09:36:15.270>
labels = ['3.11', 'type-bug', 'expert-email', '3.10', '3.9']
title = 'EmailMessage bad encoding for international domain'
updated_at = <Date 2021-12-13.17:50:29.456>
user = 'https://github.com/Julien00859'

activity = <Date 2021-12-13.17:50:29.456>
actor = 'iritkatriel'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['email']
creation = <Date 2020-02-26.09:36:15.270>
creator = 'Julien Castiaux'
dependencies = []
files = []
hgrepos = []
issue_num = 39757
keywords = ['patch']
message_count = 5.0
messages = ['362687', '362801', '362802', '362906', '408472']
nosy_count = 4.0
nosy_names = ['barry', 'r.david.murray', 'Julien Castiaux', 'iritkatriel']
pr_nums = ['18667']
priority = 'normal'
resolution = None
stage = 'needs patch'
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue39757'
versions = ['Python 3.9', 'Python 3.10', 'Python 3.11']

Activity

1. Julien00859 commented on Feb 26, 2020

   

   Julien00859mannequin

   on Feb 26, 2020

   MannequinAuthor

   More actions

   Affected python version: 3.5 and above (did test them all except 3.9)

   Steps to reproduce:

     from mail.message import EmailMessage
     from mail.policy import SMTP
   
     msg = EmailMessage(policy=SMTP)
     msg['To'] = 'Joe <joe@examplé.com>'  # notice the é in the domain
     print(msg.as_string())

   It prints

   To: "Joe <joe@=?utf-8?q?exampl=C3=A9?=.com>"
   

   But it should be

   To: "Joe <[email protected]>"
   

   While b64/qp can be used to encode most non-ascii headers, the domain part of an email address is an exception. According to IDNA2008 (rfc5890 , rfc5891), non-ascii domain should be encoded using the punycode algorithm and the ACE prefix.
2. Julien00859

   added

   topic-email

   type-bugAn unexpected behavior, bug, or errorAn unexpected behavior, bug, or error

   on Feb 26, 2020
3. Julien00859 commented on Feb 27, 2020

   

   Julien00859mannequin

   on Feb 27, 2020

   MannequinAuthor

   More actions

   Duplicate of https://bugs.python.org/issue39757
4. Julien00859

   closed this as completedon Feb 27, 2020
5. Julien00859 commented on Feb 27, 2020

   

   Julien00859mannequin

   on Feb 27, 2020

   MannequinAuthor

   More actions

   Woops wrong copie/paste, here is the correct link: https://bugs.python.org/issue11783
6. bitdancer commented on Feb 28, 2020

   

   bitdancer

   on Feb 28, 2020

   Member

   More actions

   This is not actually a duplicate of 11783. Rereading (parts of) that issue, we decided we currently have no good way to do automatic conversion between unicode and internationalized domains, so the user of the library has to do it themselves. This means that the bug *here* is that the new email API is *wrongly* encoding the non-ascii in the domain by using an encoded word. I'm surprised at that; I thought I'd guarded against it.

   What should be happening here is that an error should be raised when that header is set (or possibly when it is accessed/serialized, but when set would be better I think) saying that there is non-ascii in the domain part.
7. bitdancer

   reopened this on Feb 28, 2020
8. bitdancer

   changed the title [-]EmailMessage wrong encoding for international domain[/-] [+]EmailMessage bad encoding for international domain[/+] on Feb 28, 2020
9. iritkatriel commented on Dec 13, 2021

   

   iritkatriel

   on Dec 13, 2021

   Member

   More actions

   Reproduced on 3.11.
10. iritkatriel

    added

    3.9 (EOL)end of lifeend of life

    3.10 (EOL)end of lifeend of life

    3.11only security fixesonly security fixes

    on Dec 13, 2021
11. ezio-melotti

    transferred this issue fromon Apr 10, 2022
12. iritkatriel

    added

    stdlibStandard Library Python modules in the Lib/ directoryStandard Library Python modules in the Lib/ directory

    on Nov 23, 2023
13. bitdancer

    closed this as completedin #122540on May 1, 2026
14. bitdancer

    added a commit that references this issue on May 1, 2026

    gh-83938, gh-122476: Stop incorrectly RFC 2047 encoding non-ASCII ema…

    d96ffc1

Issue actions