VB.NET

Read Delivery-Status Fields from a Bounce

Demonstrates the Chilkat Email.GetDeliveryStatusInfo method, which returns a named field from the message/delivery-status part of a delivery-status notification (DSN). It should be called only for an email identified as a delivery-status notification. This example loads a bounce message and reads its Action, Status, and Final-Recipient fields.

Background: When a message can't be delivered, the mail system returns a bounce as a multipart/report whose message/delivery-status part carries machine-readable fields: Action (e.g. failed), Status (a numeric code like 5.1.1 meaning "no such mailbox"), and Final-Recipient (the address that failed). Parsing these lets a program automatically detect hard bounces and prune bad addresses from a mailing list.

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VB.NET

Dim success As Boolean = False

'  Demonstrates the GetDeliveryStatusInfo method, which returns a field from the
'  message/delivery-status part of a delivery-status notification (DSN / bounce).
'  Call it only for an email that is a delivery-status notification.

Dim email As New Chilkat.Email

success = email.LoadEml("qa_data/eml/dsn_bounce.eml")
If (success = False) Then
    Debug.WriteLine(email.LastErrorText)
    Exit Sub
End If


'  Read individual fields from the message/delivery-status part.
Debug.WriteLine("Action: " & email.GetDeliveryStatusInfo("Action"))
Debug.WriteLine("Status: " & email.GetDeliveryStatusInfo("Status"))
Debug.WriteLine("Final-Recipient: " & email.GetDeliveryStatusInfo("Final-Recipient"))

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