Z nativních klientů: Outlook, Windows Mail, Thunderbird............
Možné to je i z některých Webových rozhraní (např. Gmail to umí).
Principem je ovšem vždy to, že se zapasuje obrázek přímo do těla emailu.
Může to vypadat takto:
This is a multipart message in mime format.
--boundaryB6C04B03_mixed
Content-Type: multipart/related; boundary="boundary308F8714_related"
--boundary308F8714_related
Content-Transfer-Encoding: quoted-printable
Content-Type: text/html; charset="windows-1250"
Content-Disposition: inline
Content-Length: 967
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html><head><title></title>
<meta http-equiv=3D"Content-Type" content=3D"text/html; charset=3Dwindo=
ws-1250">
<meta http-equiv=3D"Content-Style-Type" content=3D"text/css">
<style type=3D"text/css"><!--
body {
margin: 10px 10px 10px 10px;
background-color: #ffffff;
}
--></style>
</head>
<body>
<p style=3D" text-align: left; text-indent: 0px; padding: 0px 0px 0px 0=
px; margin: 0px 0px 0px 0px;"><span style=3D" font-size: 10pt; font-fami=
ly: 'Arial', 'Helvetica', sans-serif; font-style: normal; font-weight: b=
old; color: #000000; background-color: transparent; text-decoration: non=
e;">Podm=EDnky naleznete v p=F8ilo=9Een=E9 prezentaci.</span></p>
<p style=3D" text-align: left; text-indent: 0px; padding: 0px 0px 0px 0=
px; margin: 0px 0px 0px 0px;"><img border=3D0 width=3D1099 height=3D825 =
alt=3D"" hspace=3D1 vspace=3D1 src=3D"cid:_1.jpg"></p>
</body></html>
--boundary308F8714_related
Content-Transfer-Encoding: base64
Content-Type: image/jpeg; name="_1.jpg"
Content-Disposition: inline; filename="_1.jpg"
Content-Length: 102998
Content-Id: <_1.jpg>
/9j/4AAQSkZJRgABAQEAYABgAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8UHRofHh0a
HBwgJC4nICIsIxwcKDcpLDAxNDQ0Hyc5PTgyPC4zNDL/2wBDAQkJCQwLDBgNDRgyIRwhMjIyMjIy
MjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjL/wAARCAM5BEsDASIA
AhEBAxEB/8QAHwAAAQUBAQEBAQEAAAAAAAAAAAECAwQFBgcICQoL/8QAtRAAAgEDAwIEAwUFBAQA
AAF9AQIDAAQRBRIhMUEGE1FhByJxFDKBkaEII0KxwRVS0fAkM2JyggkKFhcYGRolJicoKSo0NTY3
ODk6Q0RFRkdISUpTVFVWV1hZWmNkZWZnaGlqc3R1dnd4eXqDhIWGh4iJipKTlJWWl5iZmqKjpKWm
....
(Může jich obsahovat libovolné množství).