johndrinkwater · August 11, 2017 13:44
diff --git a/example.eml b/example.eml
 X-This: is a header, as email passes through servers, it gets prepended
 Received: from email.server [IP.AD.DRE.SS]
 	by other.server with POP3 (fetchmail-6.3.20)
 	for <user@localhost> (single-drop); Wed, 09 Aug 2017 18:07:16 +0100 (BST)
 DKIM-Signature: s=ecurity; i=nformation
 From: "John Drinkwater’s name" <[email protected]>
 To: "You, the reader" <[email protected]>
 Date: Wed, 9 Aug 2017 17:03:44 +0000
 Message-ID: <[email protected]>
 X-Mailer: Typical Header Junk Here 1.0.30
 X-Extended-Header: To allow for expansion, X- prefixes exist
 Content-Type: multipart/alternative; boundary="_----------=_MCPart_343795799"
 MIME-Version: 1.0
 Subject: =?utf-8?Q?Email=20is=20legacy,=20text=20needs=20escaping?=

 (The above line is intentionally blank & delimits contents from headers)
 This is a multi-part message in MIME format
 (The majority of email clients in 2017 will never show this, as this is
 for clients that don’t support MIME format… which is pretty old itself!)

 --_----------=_MCPart_343795799
 Content-Type: text/plain; charset="utf-8"; format="fixed"
 Content-Transfer-Encoding: quoted-printable

 Now we are onto the juicy bit! This is an email, but in plain text. It
 wont have hyperlinks, or *bold* emphasis unless your client renders
 that. Lines stick to a certain line length because, again, ~legacy~!
 Terminals used to be a certain size, so should email! And this faulty
 assumption made some email server software have issues with lines longer
 than the expected terminal width (with buffers) so they made the
 standard encourage wrapping.

 The above headers for this /part/ mention quoted-printable, a method of
 escaping characters that cannot be shown in the original limited set of
 characters that email accepted.

 That means that even things like =C2=A3 need to be converted to this
 format. (That is a £ for the sake of this demo. This line is technically
 corrupt!)

 What does multi-part mean? Email you typically send contains 3 unique
 messages, one mentioned above for the oldest clients to say your message
 is using the new system, another that is plain text, and the common one,
 a Web styled version built with HTML. Users with some clients have an
 option to view either, to reduce phishing, to make email more readable,
 or to reduce storage size.

 If someone chooses to view this version, they see
 http://i.imgur.com/5lVioPt.png

 --_----------=_MCPart_343795799
 Content-Type: text/html; charset="utf-8"
 Content-Transfer-Encoding: quoted-printable

 <!DOCTYPE html><head>
    <title>Now we’re onto the modern age of publishing!</title>
    <meta charset=3D"UTF-8">
    <style type=3D"text/css">
        p, .awesome_css_here {
            font-family: 'Comic Sans MS'=2C sans-serif;
        }
    </style>
 </head>
 <body style=3D"margin:0px; padding:0px;" bgcolor=3D"#f3f3f3">
 <p>Isn’t this awesome? Kinda HTML inside an email client! But wait, every=
 client has different behaviour, rendering engines, download behaviour for=
 images etc.</p>
 <p>What are those =3D (=, again, corruption) at the line ends? More      =
 legacy reasons, sorry! Some users prefer email to display lines unwrapped=
 at whatever line their client can show. Bugginess in unwrapping caused   =
 them to think over their initial design and make new formatting          =
 behaviours, lines ending in an equals tells the client to append it to   =
 the one above.</p>
 <p>If someone chooses to view this version, they see                     =
 http://i.imgur.com/v1n3Lz5.png</p>
 </body>
 </html>
 --_----------=_MCPart_343795799--
	X-This: is a header, as email passes through servers, it gets prepended
	Received: from email.server [IP.AD.DRE.SS]
	by other.server with POP3 (fetchmail-6.3.20)
	for <user@localhost> (single-drop); Wed, 09 Aug 2017 18:07:16 +0100 (BST)
	DKIM-Signature: s=ecurity; i=nformation
	From: "John Drinkwater’s name" <[email protected]>
	To: "You, the reader" <[email protected]>
	Date: Wed, 9 Aug 2017 17:03:44 +0000
	Message-ID: <[email protected]>
	X-Mailer: Typical Header Junk Here 1.0.30
	X-Extended-Header: To allow for expansion, X- prefixes exist
	Content-Type: multipart/alternative; boundary="_----------=_MCPart_343795799"
	MIME-Version: 1.0
	Subject: =?utf-8?Q?Email=20is=20legacy,=20text=20needs=20escaping?=

	(The above line is intentionally blank & delimits contents from headers)
	This is a multi-part message in MIME format
	(The majority of email clients in 2017 will never show this, as this is
	for clients that don’t support MIME format… which is pretty old itself!)

	--_----------=_MCPart_343795799
	Content-Type: text/plain; charset="utf-8"; format="fixed"
	Content-Transfer-Encoding: quoted-printable

	Now we are onto the juicy bit! This is an email, but in plain text. It
	wont have hyperlinks, or bold emphasis unless your client renders
	that. Lines stick to a certain line length because, again, ~legacy~!
	Terminals used to be a certain size, so should email! And this faulty
	assumption made some email server software have issues with lines longer
	than the expected terminal width (with buffers) so they made the
	standard encourage wrapping.

	The above headers for this /part/ mention quoted-printable, a method of
	escaping characters that cannot be shown in the original limited set of
	characters that email accepted.

	That means that even things like =C2=A3 need to be converted to this
	format. (That is a £ for the sake of this demo. This line is technically
	corrupt!)

	What does multi-part mean? Email you typically send contains 3 unique
	messages, one mentioned above for the oldest clients to say your message
	is using the new system, another that is plain text, and the common one,
	a Web styled version built with HTML. Users with some clients have an
	option to view either, to reduce phishing, to make email more readable,
	or to reduce storage size.

	If someone chooses to view this version, they see
	http://i.imgur.com/5lVioPt.png

	--_----------=_MCPart_343795799
	Content-Type: text/html; charset="utf-8"
	Content-Transfer-Encoding: quoted-printable

	<!DOCTYPE html><head>
	<title>Now we’re onto the modern age of publishing!</title>
	<meta charset=3D"UTF-8">
	<style type=3D"text/css">
	p, .awesome_css_here {
	font-family: 'Comic Sans MS'=2C sans-serif;
	}
	</style>
	</head>
	<body style=3D"margin:0px; padding:0px;" bgcolor=3D"#f3f3f3">
	<p>Isn’t this awesome? Kinda HTML inside an email client! But wait, every=
	client has different behaviour, rendering engines, download behaviour for=
	images etc.</p>
	<p>What are those =3D (=, again, corruption) at the line ends? More =
	legacy reasons, sorry! Some users prefer email to display lines unwrapped=
	at whatever line their client can show. Bugginess in unwrapping caused =
	them to think over their initial design and make new formatting =
	behaviours, lines ending in an equals tells the client to append it to =
	the one above.</p>
	<p>If someone chooses to view this version, they see =
	http://i.imgur.com/v1n3Lz5.png</p>
	</body>
	</html>
	--_----------=_MCPart_343795799--