使用 smtputf8 修复 Python smtplib 和国际化错误

Question

在名称中使用非 ascii 字符时，python smtplib 出现问题。部分错误代码 - 是

server does not advertise the required SMTPUTF8 capability

我已经在网上查了解决方案，也在 stackoverflow 中查看了没有解决方案。

使用相同的

smtp

在其他具有相同发件人名称的邮件客户端上它可以工作，所以我认为这可以通过代码解决，因为我无法编辑服务器配置。

请提供解决方案指南或示例以帮助解决此问题。

请参阅下面带有回溯的代码的 sn-p。

# the problem is this line below. How do I make it work regardless 
# since i have no means of advertising smtputf8 from there server.
# Thunderbird doesn't have problem with the name when used as client.

data['from_name'] = "Böy" # problem is the ö
data['from_email'] = "user@example.com"
msg = MIMEMultipart()
msg['To'] = "{to_name} <{to_email}>".format(**data)
msg['From'] = "{} <{}>".format(data['from_name'], data['from_email'])
msg['Date'] = formatdate(localtime=True)
msg['Subject'] = subject
msg.attach(MIMEText(body, 'html'))

smtp_server.send_message(msg) # exception is raised here

追溯：

`Traceback (most recent call last):
  File "Emailer.py", line 460, in <module>
    main(args)
  File "Emailer.py", line 447, in main
    sender.send()
  File "Emailer.py", line 386, in send
    smtp_server.send_message(msg)
  File "/usr/local/Cellar/python3/3.6.4_2/Frameworks/Python.framework/Versions/3.6/lib/python3.6/smtplib.py", line 952, in send_message
    "One or more source or delivery addresses require"
smtplib.SMTPNotSupportedError: One or more source or delivery addresses require internationalized email support, but the server does not advertise the required SMTPUTF8 capability`

Answer 1

我无法重现您的问题。使用以下增强代码，我有一个似乎是MCVE：

from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.utils import formatdate


data = {'to_name': 'me', 'to_email': 'me@example.net'}
subject = 'Hellö'
body = 'Hellö'

data['from_name'] = "Böy" # problem is the ö
data['from_email'] = "user@example.com"
msg = MIMEMultipart()
msg['To'] = "{to_name} <{to_email}>".format(**data)
msg['From'] = "{} <{}>".format(data['from_name'], data['from_email'])
msg['Date'] = formatdate(localtime=True)
msg['Subject'] = subject
msg.attach(MIMEText(body, 'html'))

print(msg.as_string())

但是当我运行它时，Python 会生成一个完全正常的、完全 7 位的 US-ASCII 消息，其中所有部分的编码都与不支持 SMTPUTF8 的旧服务器的编码完全相同。

Content-Type: multipart/mixed; boundary="===============2605356503081581034=="
MIME-Version: 1.0
To: me <me@example.net>
From: =?utf-8?b?QsO2eSA8dXNlckBleGFtcGxlLmNvbT4=?=
Date: Mon, 13 Aug 2018 10:56:02 +0300
Subject: =?utf-8?b?SGVsbMO2?=

--===============2605356503081581034==
Content-Type: text/html; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: base64

SGVsbMO2

--===============2605356503081581034==--

但是，我会注意到将裸露的 MIMEMultipart 实例化为您的顶级消息并不真正正确。您应该有一个 Message 对象，然后向其中添加 MIME 部分。但这仍然使用有些复杂的遗留 Python email API；使用 3.3 中引入并在 3.6 中成为首选 API 的新 API，您应该从 EmailMessage 开始并从那里获取。

无论如何，如果您只有一个正文部分，则不应将其包装在多部分消息中。只需创建一封电子邮件并将文本部分直接附加到该邮件。 （拥有比您需要的更复杂的 MIME 结构本身并没有错误，但是增加不必要的复杂性和开销是愚蠢的。）