Email 5.1

The email package is extended to be able to parse and generate email messages

in bytes format.

* New functions :func:`~email.message_from_bytes` and

:func:`~email.message_from_binary_file`, and new classes

:class:`~email.parser.BytesFeedParser` and :class:`~email.parser.BytesParser`

allow binary message data to be parsed into model objects.

* Given bytes input to the model, :meth:`~email.message.Message.get_payload`

will by default decode a message body that has a

:mailheader:`Content-Transfer-Encoding` of `8bit` using the charset specified

in the MIME headers and return the resulting string.

* Given bytes input to the model, :class:`~email.generator.Generator` will

convert message bodies that have a :mailheader:`Content-Transfer-Encoding` of

8bit to instead have a 7bit Content-Transfer-Encoding.

* New class :class:`~email.generator.BytesGenerator` produces bytes

as output, preserving any unchanged non-ASCII data that was

present in the input used to build the model, including message bodies

with a :mailheader:`Content-Transfer-Encoding` of 8bit.

(Proposed and implemented by R. David Murray, :issue:`4661`.)