Sample code for 30+ languages & platforms
AutoIt

Get the Content-ID of an Attachment

See more Email Object Examples

Demonstrates the Chilkat Email.GetAttachmentContentID method, which returns the Content-ID header field for the Nth attachment. The index is zero-based, so the first attachment is 0. This example adds an attachment and reads its Content-ID (which may be empty when none was assigned).

Background: A Content-ID is a unique identifier for a MIME part. It is essential for inline "related" resources, where HTML references an image by cid:, but ordinary file attachments usually have none. Reading it is useful when inspecting how a message is assembled, or when distinguishing parts that are referenced from the body versus those meant purely as downloadable attachments.

Chilkat AutoIt Downloads

AutoIt
;  Demonstrates the GetAttachmentContentID method, which returns the Content-ID header
;  field for the Nth attachment.  The index is zero-based (the first attachment is 0).

$oEmail = ObjCreate("Chilkat.Email")
$oEmail.Subject = "Attachment Content-ID"

$oEmail.AddStringAttachment("notes.txt","Some notes.")

;  Get the Content-ID of the first attachment (may be empty if none was assigned).
Local $sCid = $oEmail.GetAttachmentContentID(0)
ConsoleWrite("Attachment 0 Content-ID: " & $sCid & @CRLF)