I will show below a email code that embed a image, and refer to that image on a "img" tag by his "src" property, what is normal, but that image is one of the attachments, and is accessed by a "cid:" prefix, I think it means "Content ID".
below is the img part of the email body
<IMG border=3D0 hspace=3D0 alt=3D"" =
align=3Dbaseline=20
src=3D"cid:698DDDB61CF04A4CADC5084C38B7AF38@tvdev01">
now the content ID
------=_NextPart_000_0007_01CE9B3A.AC5A71A0
Content-Type: image/jpeg;
name="sample.JPG"
Content-Transfer-Encoding: base64
Content-ID: <698DDDB61CF04A4CADC5084C38B7AF38@tvdev01>
I got no problem in this source, and no problem at all. But I don´t know if this characteristics turn that HTML language into a specific HTML language just for emails, and if this specific language have a name.
Lets do the asks:
1) Is that a specific language? 2) What is his name? 3) Where to find documentation about him?
the full email code below:
From: "paulo" <paulo@techvision.com.br>
To: "qualemail@yahoo.com.br"
Subject: sample of email specific html
Date: Sat, 17 Aug 2013 11:12:28 -0300
MIME-Version: 1.0
Content-Type: multipart/related;
type="multipart/alternative";
boundary="----=_NextPart_000_0007_01CE9B3A.AC5A71A0"
X-Priority: 3
X-MSMail-Priority: Normal
X-Unsent: 1
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157
This is a multi-part message in MIME format.
------=_NextPart_000_0007_01CE9B3A.AC5A71A0
Content-Type: multipart/alternative;
boundary="----=_NextPart_001_0008_01CE9B3A.AC5A71A0"
------=_NextPart_001_0008_01CE9B3A.AC5A71A0
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
a text and below the image
------=_NextPart_001_0008_01CE9B3A.AC5A71A0
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content=3D"text/html; charset=3Diso-8859-1" =
http-equiv=3DContent-Type>
<META name=3DGENERATOR content=3D"MSHTML 8.00.6001.23501">
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT size=3D2 face=3DArial>a text and below the image</FONT></DIV>
<DIV><FONT size=3D2 face=3DArial><IMG border=3D0 hspace=3D0 alt=3D"" =
align=3Dbaseline=20
src=3D"cid:698DDDB61CF04A4CADC5084C38B7AF38@tvdev01"></FONT></DIV></BODY>=
</HTML>
------=_NextPart_001_0008_01CE9B3A.AC5A71A0--
------=_NextPart_000_0007_01CE9B3A.AC5A71A0
Content-Type: image/jpeg;
name="sample.JPG"
Content-Transfer-Encoding: base64
Content-ID: <698DDDB61CF04A4CADC5084C38B7AF38@tvdev01>
/9j/4AAQSkZJRgABAQEAYABgAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8UHRofHh0a
HBwgJC4nICIsIxwcKDcpLDAxNDQ0Hyc5PTgyPC4zNDL/2wBDAQkJCQwLDBgNDRgyIRwhMjIyMjIy
MjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjL/wAARCAAVABUDASIA
AhEBAxEB/8QAHwAAAQUBAQEBAQEAAAAAAAAAAAECAwQFBgcICQoL/8QAtRAAAgEDAwIEAwUFBAQA
AAF9AQIDAAQRBRIhMUEGE1FhByJxFDKBkaEII0KxwRVS0fAkM2JyggkKFhcYGRolJicoKSo0NTY3
ODk6Q0RFRkdISUpTVFVWV1hZWmNkZWZnaGlqc3R1dnd4eXqDhIWGh4iJipKTlJWWl5iZmqKjpKWm
p6ipqrKztLW2t7i5usLDxMXGx8jJytLT1NXW19jZ2uHi4+Tl5ufo6erx8vP09fb3+Pn6/8QAHwEA
AwEBAQEBAQEBAQAAAAAAAAECAwQFBgcICQoL/8QAtREAAgECBAQDBAcFBAQAAQJ3AAECAxEEBSEx
BhJBUQdhcRMiMoEIFEKRobHBCSMzUvAVYnLRChYkNOEl8RcYGRomJygpKjU2Nzg5OkNERUZHSElK
U1RVVldYWVpjZGVmZ2hpanN0dXZ3eHl6goOEhYaHiImKkpOUlZaXmJmaoqOkpaanqKmqsrO0tba3
uLm6wsPExcbHyMnK0tPU1dbX2Nna4uPk5ebn6Onq8vP09fb3+Pn6/9oADAMBAAIRAxEAPwD2vUdf
sdNvbeylaR7md41CRrkIHfYrOxwqAnO3cQXKlUDN8tGta0NESGaWwu57d3CyTQGMiHLKq5VnDuSW
wFjV2J4AJIB1Ky9Jg1qK41CTVr20niluGa0ht4Cn2eIEhVZyfnJUKx4GGZgCRtwAaEE8N1bxXFvL
HNBKgeOSNgyupGQQRwQRzmipKKAI54Ibq3lt7iKOaCVCkkcihldSMEEHggjjFZemeFdC0TUZb7Sd
MgsJpohDItoDFG6gkgmNcIWBJ+YjdgkZxxRRQBsUUUUAf//Z
------=_NextPart_000_0007_01CE9B3A.AC5A71A0--
thanks in advance