以下 help からコピペ。ドラフトバッファで C-c C-x ? で以下が出る。
ファイルを添付したいときはドラフトバッファで C-c C-x
MIME editor mode: MIME minor mode for editing the tagged MIME message. In this mode, basically, the message is composed in the tagged MIME format. The message tag looks like: --[[text/plain; charset=ISO-2022-JP][7bit]] The tag specifies the MIME content type, subtype, optional parameters and transfer encoding of the message following the tag. Messages without any tag are treated as `text/plain' by default. Charset and transfer encoding are automatically defined unless explicitly specified. Binary messages such as audio and image are usually hidden. The messages in the tagged MIME format are automatically translated into a MIME compliant message when exiting this mode. Available charsets depend on Emacs version being used. The following lists the available charsets of each emacs. Without mule: US-ASCII and ISO-8859-1 (or other charset) are available. With mule: US-ASCII, ISO-8859-* (except for ISO-8859-5), KOI8-R, ISO-2022-JP, ISO-2022-JP-2, EUC-KR, CN-GB-2312, CN-BIG5 and ISO-2022-INT-1 are available. ISO-2022-JP-2 and ISO-2022-INT-1 charsets used in mule is expected to be used to represent multilingual text in intermixed manner. Any languages that has no registered charset are represented as either ISO-2022-JP-2 or ISO-2022-INT-1 in mule. If you want to use non-ISO-8859-1 charset in Emacs 19 or XEmacs without mule, please set variable `default-mime-charset'. This variable must be symbol of which name is a MIME charset. If you want to add more charsets in mule, please set variable `charsets-mime-charset-alist'. This variable must be alist of which key is list of charset and value is symbol of MIME charset. If name of coding-system is different as MIME charset, please set variable `mime-charset-coding-system-alist'. This variable must be alist of which key is MIME charset and value is coding-system. Following commands are available in addition to major mode commands: [make single part] C-c C-x C-t insert a text message. C-c C-x TAB insert a (binary) file. C-c C-x C-e insert a reference to external body. C-c C-x C-v insert a voice message. C-c C-x C-y insert a mail or news message. C-c C-x RET insert a mail message. C-c C-x C-s insert a signature file at end. C-c C-x C-k insert PGP public key. C-c C-x t insert a new MIME tag. [make enclosure (maybe multipart)] C-c RET C-a enclose as multipart/alternative. C-c RET C-p enclose as multipart/parallel. C-c RET RET enclose as multipart/mixed. C-c RET C-d enclose as multipart/digest. C-c RET C-s enclose as PGP signed. C-c RET C-e enclose as PGP encrypted. C-c RET C-q enclose as verbose mode (to avoid to expand tags) [other commands] C-c C-x 7 set transfer-level as 7. C-c C-x 8 set transfer-level as 8. C-c C-x / set message splitting mode. C-c C-x v set PGP-sign mode. C-c C-x h set PGP-encryption mode. C-c C-x p preview editing MIME message. C-c C-x C-z exit and translate into a MIME compliant message. C-c C-x ? show this help. M-x mime-edit-maybe-translate exit and translate if in MIME mode, then split. Additional commands are available in some major modes: C-c C-c exit, translate and run the original command. C-c C-s exit, translate and run the original command. The following is a message example written in the tagged MIME format. TABs at the beginning of the line are not a part of the message: This is a conventional plain text. It should be translated into text/plain. --[[text/plain]] This is also a plain text. But, it is explicitly specified as is. --[[text/plain; charset=ISO-8859-1]] This is also a plain text. But charset is specified as iso-8859-1. ¡Hola! Buenos días. ¿Cómo está usted? --[[text/enriched]] This is a <bold>enriched text</bold>. --[[image/gif][base64]]...image encoded in base64 here... --[[audio/basic][base64]]...audio encoded in base64 here... User customizable variables (not documented all of them): mime-edit-prefix Specifies a key prefix for MIME minor mode commands. mime-ignore-preceding-spaces Preceding white spaces in a message body are ignored if non-nil. mime-ignore-trailing-spaces Trailing white spaces in a message body are ignored if non-nil. mime-auto-hide-body Hide a non-textual body message encoded in base64 after insertion if non-nil. mime-transfer-level A number of network transfer level. It should be bigger than 7. If you are in 8bit-through environment, please set 8. mime-edit-voice-recorder Specifies a function to record a voice message and encode it. The function `mime-edit-voice-recorder-for-sun' is for Sun SparcStations. mime-edit-mode-hook Turning on MIME mode calls the value of mime-edit-mode-hook, if it is non-nil. mime-edit-translate-hook The value of mime-edit-translate-hook is called just before translating the tagged MIME format into a MIME compliant message if it is non-nil. If the hook call the function mime-edit-insert-signature, the signature file will be inserted automatically. mime-edit-exit-hook Turning off MIME mode calls the value of mime-edit-exit-hook, if it is non-nil.