In the context of email, mime may have two different definitions:
The mime is just the text structure of an email message (known as mime message).
Delivered-To: [email protected] Received: by 2002:a05:6504:519b:0:0:0:0 with SMTP id z27csp820130ltq; Date: Fri, 12 Jun 2020 21:08:18 +0200 To: [email protected] Subject: Without hosts dkim test ! User-Agent: Heirloom mailx 12.5 7/5/10 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: <[email protected]> From: [email protected] (root) cc: [email protected] bcc: [email protected] This is the body of the email
The MIME is specified by the following RFCs if you want to get all details
|RFC2045||Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies|
|RFC2046||Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types (See also media type)|
|RFC2047||MIME (Multipurpose Internet Mail Extensions) Part Three: Message Header Extensions for Non-ASCII Text|
mime is also used widely to refer to the media type (content-type) because this is where it comes from.
An email may be sent with multiformat (with multiple media types)
- For an HTML email
Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable
- for a text email
Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable