Question

我目前正在编写一个应用程序，需要将电子邮件加载到内存中，添加附件并将相同的电子邮件发送回用户。这在过去运作良好，但我目前面临的问题是Content-Transfer-Encoding base64发送了一封电子邮件。

我发现了一个在线脚本，它将内置的Python电子邮件消息对象转换为multipart，但是每当我这样做时，原始电子邮件都不会以base64形式发送，现在每当我重新发送电子邮件时都会以纯文本形式显示。

有谁知道我怎么解决它？已经添加了（主要是已编辑的）电子邮件以及我用于将电子邮件转换为多部分的代码。感谢您的帮助。

电子邮件

# Before conversion
From: ██████████ <█████@██████.com>
To: ████████ <███████@██████.com>
Subject: █████████
Date: Fri, ██ ███ 2017 00:18:17 +0200
Content-Language: nl-NL
Content-Type: text/html; charset="utf-8"
Content-Transfer-Encoding: base64
MIME-Version: 1.0

cmVkYWN0ZWRyZWRhY3RlZHJlZGFjdGVkcmVkYWN0ZWRyZWRhY3RlZHJlZGFjdGVkcmVkYWN0ZWRy
ZWRhY3RlZHJlZGFjdGVkcmVkYWN0ZWRyZWRhY3RlZHJlZGFjdGVkcmVkYWN0ZWRyZWRhY3RlZHJl
ZGFjdGVkcmVkYWN0ZWRyZWRhY3RlZHJlZGFjdGVkcmVkYWN0ZWRyZWRhY3RlZA0K


# After conversion
Content-Type: multipart/mixed; boundary="===============0883378942=="
MIME-Version: 1.0
From: ██████████ <█████@██████.com>
To: ████████ <███████@██████.com>
Subject: █████████
Date: Fri, ██ ███ 2017 00:18:17 +0200
Content-Language: nl-NL
Content-Transfer-Encoding: base64
MIME-Version: 1.0
--===============0883378942==
Content-Type: text/html; charset="utf-8"
cmVkYWN0ZWRyZWRhY3RlZHJlZGFjdGVkcmVkYWN0ZWRyZWRhY3RlZHJlZGFjdGVkcmVkYWN0ZWRy
ZWRhY3RlZHJlZGFjdGVkcmVkYWN0ZWRyZWRhY3RlZHJlZGFjdGVkcmVkYWN0ZWRyZWRhY3RlZHJl
ZGFjdGVkcmVkYWN0ZWRyZWRhY3RlZHJlZGFjdGVkcmVkYWN0ZWRyZWRhY3RlZA0K
--===============0883378942==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment; filename="foo.txt"
Hello world
--===============0883378942==--

普通到多部分代码

# If this method is not used on an email object
# A `TypeError` is raised with the message "Attach is not valid on a message with a non-multipart payload"

def mail_to_multipart(mail):
    """
    Convert an email to a multipart email
    :param mail: Email object
    :return: None
    """
    if mail.is_multipart():
        return mail

    mail_new = MIMEMultipart("mixed")
    headers = list((k, v) for (k, v) in mail.items() if k != "Content-Type")

    for k, v in headers:
        mail_new[k] = v

    for k, v in headers:
        del mail[k]

    mail_new.attach(mail)
    return mail_new

Answer 1

显然，该问题与旧的多部分块中未保留的Content-Transfer-Encoding标题有关，方法是更改以下行：

headers = list((k, v) for (k, v) in mail.items() if k != "Content-Type")

对此：

headers = list((k, v) for (k, v) in mail.items() if k not in ("Content-Type", "Content-Transfer-Encoding"))

修正了问题

附加对具有非多部分有效负载的消息无效

电子邮件

普通到多部分代码

1 个答案: