B4X

Convert a MIME Entity to multipart/mixed

Demonstrates the Chilkat Mime.ConvertToMultipartMixed method, which wraps the current entity in a new outer multipart/mixed, making the original the first child. It takes no arguments.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: This is how you turn an existing single-part message into one that can hold attachments — rather than rebuilding it, you wrap it, and its content becomes the first child of a new multipart/mixed. Message-level and custom headers are carried onto the new outer entity so the message identity is preserved. Afterward, AppendPartFromFile adds attachments beside the original body.

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B4X

Dim success As Boolean = False

Dim mime As ChilkatMime
mime.Initialize
success = mime.LoadMimeFile("qa_data/message.eml")
If success = False Then
    Log(mime.LastErrorText)
    Return
End If


'  Wrap the current entity in a new outer multipart/mixed entity.  The original entity becomes the
'  first child, which is what you do to add attachments to an existing single-part message.
success = mime.ConvertToMultipartMixed
If success = False Then
    Log(mime.LastErrorText)
    Return
End If


'  Now attachments can be appended alongside the original content.
success = mime.AppendPartFromFile("qa_data/report.pdf")
If success = False Then
    Log(mime.LastErrorText)
    Return
End If


Log("Number of parts: " & mime.NumParts)