When an e-mail with an attachment is added to the SMTP client the attachment has different properties. One of them is the filename, another one is the MIME type, there is an optional property named Content-ID (cid). Once I set the value of this property, I can reference that value from the html message body. For example, if an image attachment has the property cid: myimage, then I can reference it inside the message in an img tag as <img src=cid:myimage> this will display the image directly in the body of the message that can be seen right away, but not as an attachment that I have to click on to open.
The first reference that you provided describe sending e-mail in LabView 2010. In LabView 2014 it seems it is done by different vis. By the way, there is an option to set Content-type of an attachment in LabView 2010 (but not Content-ID), that I just did not see in LabView 2014.
The second reference shows how to send-mails using constructors, I am sure it must be possible to set Content-ID following this path, I just do not know how exactly to do that.
