# `email.mime`: Creating email and MIME objects from scratch

Source code: Lib/email/mime/

This module is part of the legacy (`Compat32`) email API. Its functionality is partially replaced by the `contentmanager` in the new API, but in certain applications these classes may still be useful, even in non-legacy code.

Ordinarily, you get a message object structure by passing a file or some text to a parser, which parses the text and returns the root message object. However you can also build a complete message structure from scratch, or even individual `Message` objects by hand. In fact, you can also take an existing structure and add new `Message` objects, move them around, etc. This makes a very convenient interface for slicing-and-dicing MIME messages.

You can create a new object structure by creating `Message` instances, adding attachments and all the appropriate headers manually. For MIME messages though, the `email` package provides some convenient subclasses to make things easier.

Here are the classes:

class email.mime.base.MIMEBase(_maintype, _subtype, *, policy=compat32, **_params)

  Module: `email.mime.base`

  This is the base class for all the MIME-specific subclasses of `Message`. Ordinarily you won’t create instances specifically of `MIMEBase`, although you could. `MIMEBase` is provided primarily as a convenient base class for more specific MIME-aware subclasses.

  _maintype is the Content-Type major type (e.g. text or image), and _subtype is the Content-Type minor type (e.g. plain or gif). _params is a parameter key/value dictionary and is passed directly to `Message.add_header`.

  If policy is specified, (defaults to the `compat32` policy) it will be passed to `Message`.

  The `MIMEBase` class always adds a Content-Type header (based on _maintype, _subtype, and _params), and a MIME-Version header (always set to `1.0`).

  Changed in version 3.6: Added policy keyword-only parameter.

class email.mime.nonmultipart.MIMENonMultipart

  Module: `email.mime.nonmultipart`

  A subclass of `MIMEBase`, this is an intermediate base class for MIME messages that are not multipart. The primary purpose of this class is to prevent the use of the `attach()` method, which only makes sense for multipart messages. If `attach()` is called, a `MultipartConversionError` exception is raised.

class email.mime.multipart.MIMEMultipart(_subtype='mixed', boundary=None, _subparts=None, *, policy=compat32, **_params)

  Module: `email.mime.multipart`

  A subclass of `MIMEBase`, this is an intermediate base class for MIME messages that are multipart. Optional _subtype defaults to mixed, but can be used to specify the subtype of the message. A Content-Type header of multipart/_subtype will be added to the message object. A MIME-Version header will also be added.

  Optional boundary is the multipart boundary string. When `None` (the default), the boundary is calculated when needed (for example, when the message is serialized).

  _subparts is a sequence of initial subparts for the payload. It must be possible to convert this sequence to a list. You can always attach new subparts to the message by using the `Message.attach` method.

  Optional policy argument defaults to `compat32`.

  Additional parameters for the Content-Type header are taken from the keyword arguments, or passed into the _params argument, which is a keyword dictionary.

  Changed in version 3.6: Added policy keyword-only parameter.

class email.mime.application.MIMEApplication(_data, _subtype='octet-stream', _encoder=email.encoders.encode_base64, *, policy=compat32, **_params)

  Module: `email.mime.application`

  A subclass of `MIMENonMultipart`, the `MIMEApplication` class is used to represent MIME message objects of major type application. _data is a string containing the raw byte data. Optional _subtype specifies the MIME subtype and defaults to octet-stream.

  Optional _encoder is a callable (i.e. function) which will perform the actual encoding of the data for transport. This callable takes one argument, which is the `MIMEApplication` instance. It should use `get_payload()` and `set_payload()` to change the payload to encoded form. It should also add any Content-Transfer-Encoding or other headers to the message object as necessary. The default encoding is base64. See the `email.encoders` module for a list of the built-in encoders.

  Optional policy argument defaults to `compat32`.

  _params are passed straight through to the base class constructor.

  Changed in version 3.6: Added policy keyword-only parameter.

class email.mime.audio.MIMEAudio(_audiodata, _subtype=None, _encoder=email.encoders.encode_base64, *, policy=compat32, **_params)

  Module: `email.mime.audio`

  A subclass of `MIMENonMultipart`, the `MIMEAudio` class is used to create MIME message objects of major type audio. _audiodata is a string containing the raw audio data. If this data can be decoded as au, wav, aiff, or aifc, then the subtype will be automatically included in the Content-Type header. Otherwise you can explicitly specify the audio subtype via the _subtype argument. If the minor type could not be guessed and _subtype was not given, then `TypeError` is raised.

  Optional _encoder is a callable (i.e. function) which will perform the actual encoding of the audio data for transport. This callable takes one argument, which is the `MIMEAudio` instance. It should use `get_payload()` and `set_payload()` to change the payload to encoded form. It should also add any Content-Transfer-Encoding or other headers to the message object as necessary. The default encoding is base64. See the `email.encoders` module for a list of the built-in encoders.

  Optional policy argument defaults to `compat32`.

  _params are passed straight through to the base class constructor.

  Changed in version 3.6: Added policy keyword-only parameter.

class email.mime.image.MIMEImage(_imagedata, _subtype=None, _encoder=email.encoders.encode_base64, *, policy=compat32, **_params)

  Module: `email.mime.image`

  A subclass of `MIMENonMultipart`, the `MIMEImage` class is used to create MIME message objects of major type image. _imagedata is a string containing the raw image data. If this data type can be detected (jpeg, png, gif, tiff, rgb, pbm, pgm, ppm, rast, xbm, bmp, webp, and exr attempted), then the subtype will be automatically included in the Content-Type header. Otherwise you can explicitly specify the image subtype via the _subtype argument. If the minor type could not be guessed and _subtype was not given, then `TypeError` is raised.

  Optional _encoder is a callable (i.e. function) which will perform the actual encoding of the image data for transport. This callable takes one argument, which is the `MIMEImage` instance. It should use `get_payload()` and `set_payload()` to change the payload to encoded form. It should also add any Content-Transfer-Encoding or other headers to the message object as necessary. The default encoding is base64. See the `email.encoders` module for a list of the built-in encoders.

  Optional policy argument defaults to `compat32`.

  _params are passed straight through to the `MIMEBase` constructor.

  Changed in version 3.6: Added policy keyword-only parameter.

class email.mime.message.MIMEMessage(_msg, _subtype='rfc822', *, policy=compat32)

  Module: `email.mime.message`

  A subclass of `MIMENonMultipart`, the `MIMEMessage` class is used to create MIME objects of main type message. _msg is used as the payload, and must be an instance of class `Message` (or a subclass thereof), otherwise a `TypeError` is raised.

  Optional _subtype sets the subtype of the message; it defaults to rfc822.

  Optional policy argument defaults to `compat32`.

  Changed in version 3.6: Added policy keyword-only parameter.

class email.mime.text.MIMEText(_text, _subtype='plain', _charset=None, *, policy=compat32)

  Module: `email.mime.text`

  A subclass of `MIMENonMultipart`, the `MIMEText` class is used to create MIME objects of major type text. _text is the string for the payload. _subtype is the minor type and defaults to plain. _charset is the character set of the text and is passed as an argument to the `MIMENonMultipart` constructor; it defaults to `us-ascii` if the string contains only `ascii` code points, and `utf-8` otherwise. The _charset parameter accepts either a string or a `Charset` instance.

  Unless the _charset argument is explicitly set to `None`, the MIMEText object created will have both a Content-Type header with a `charset` parameter, and a Content-Transfer-Encoding header. This means that a subsequent `set_payload` call will not result in an encoded payload, even if a charset is passed in the `set_payload` command. You can “reset” this behavior by deleting the `Content-Transfer-Encoding` header, after which a `set_payload` call will automatically encode the new payload (and add a new Content-Transfer-Encoding header).

  Optional policy argument defaults to `compat32`.

  Changed in version 3.5: _charset also accepts `Charset` instances.

  Changed in version 3.6: Added policy keyword-only parameter.