VB.NET

Get Email HTML Body with Images as Base64 Inline Data

See more Email Object Examples

Demonstrates how to get the email's HTML body with referenced MIME parts (i.e. related images) embedded in the HTML as base64 data.

Note: This example requires Chilkat v10.1.2 or later.

VB.NET

Dim success As Boolean = False

' ---------------------------------------------------------------------------------------------------------------------------------
' Prerequisite Knowledge:

' In HTML emails, CID (Content-ID) image references allow embedding images directly into the email as part of the message body, 
' instead of linking to external images. 

' * Each embedded image is assigned a unique Content-ID (CID) in the email�s MIME structure.
' * The CID is a unique identifier, such as image001@domain.com.

' For example: <img src="cid:image001@domain.com" alt="Embedded Image">
' ---------------------------------------------------------------------------------------------------------------------------------

' However, in HTML, you can embed image data directly into an <img> tag by using Base64 encoding. 
' This method eliminates the need for external image files by encoding the image as a string and including it within the HTML.

' For example:
' <img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUA .... RU5ErkJggg==" alt="Embedded Image">

' Chilkat added the GetHtmlBodySb method in version 10.1.2 which provides an option for gathering the 
' image data from the mulitpart/related MIME parts of the email, and replaces the "cid" img references with
' the base64 data.

Dim email As New Chilkat.Email
success = email.LoadEml("qa_data/eml/sample.eml")
If (success = False) Then
    Debug.WriteLine(email.LastErrorText)
    Exit Sub
End If


Dim sbHtml As New Chilkat.StringBuilder
Dim inlineImageData As Boolean = True
success = email.GetHtmlBodySb(inlineImageData,sbHtml)
If (success = False) Then
    Debug.WriteLine(email.LastErrorText)
    Exit Sub
End If


' The HTML with inlined base64 image data is now contained in the StringBuilder.
Dim htmlStr As String = sbHtml.GetAsString()

sbHtml.WriteFile("c:/temp/qa_output/sample.html","utf-8",False)

Debug.WriteLine("Success.")