DataFlex

Create a Delivery Status Notification (DSN)

Demonstrates the Chilkat Email.ToDsn method, which creates a new Delivery Status Notification (DSN) email in the format specified by RFC 3464, based on this email. The generated DSN is returned in the last argument, and the source email is not modified. The first argument is the human-readable explanation, the second is the delivery-status fields, and the third indicates whether to include headers only. This example builds a DSN for a received message.

Background: A DSN is the formal "bounce" a mail system returns when a message cannot be delivered. It is a multipart/report containing a human-readable explanation plus a machine-readable message/delivery-status part (with fields like Action and Status). ToDsn generates that structured report for you — useful when building a mail server or gateway that must issue standards-compliant bounces. After generating it, populate the sender/recipient fields and send.

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Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoEmail
    Variant vDsn
    Handle hoDsn
    String sTemp1

    Move False To iSuccess

    //  Demonstrates the ToDsn method, which creates a new Delivery Status Notification (DSN)
    //  email (RFC 3464) based on this email.  The generated DSN is returned in the last argument.
    //  The source email is not modified.

    Get Create (RefClass(cComChilkatEmail)) To hoEmail
    If (Not(IsComObjectCreated(hoEmail))) Begin
        Send CreateComObject of hoEmail
    End

    Get ComLoadEml Of hoEmail "qa_data/eml/received.eml" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoEmail To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Create a DSN for the received message.  The 1st argument is the human-readable
    //  explanation, the 2nd is the delivery-status fields, and the 3rd (headerOnly) is false.
    Get Create (RefClass(cComChilkatEmail)) To hoDsn
    If (Not(IsComObjectCreated(hoDsn))) Begin
        Send CreateComObject of hoDsn
    End
    Get pvComObject of hoDsn to vDsn
    Get ComToDsn Of hoEmail "The message could not be delivered to the recipient." "Action: failed; Status: 5.1.1" False vDsn To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoEmail To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Populate additional sender/recipient fields on the DSN before sending, then send it.
    Get ComGetMime Of hoDsn To sTemp1
    Showln sTemp1

    //  Note: The path "qa_data/..." is a relative local filesystem path,
    //  relative to the current working directory of the running application.


End_Procedure