Bounced Email Handling

Demonstrates how to examine emails and detect which are bounced (automated) replies. Classifies each email according to the type of bounce.

Download: Chilkat .NET Assemblies

Dim bounce As New Chilkat.Bounce()

Dim success As Boolean
success = bounce.UnlockComponent("Anything for 30-day trial")
If (success = false) Then
    MsgBox(bounce.LastErrorText)
    Exit Sub
End If


'  The mailman object is used for receiving (POP3)
'  and sending (SMTP) email.
Dim mailman As New Chilkat.MailMan()

'  Any string argument automatically begins the 30-day trial.
success = mailman.UnlockComponent("30-day trial")
If (success <> true) Then
    MsgBox(mailman.LastErrorText)
    Exit Sub
End If


'  Set the POP3 server's hostname
mailman.MailHost = "mail.chilkatsoft.com"

'  Set the POP3 login/password.
mailman.PopUsername = "myLogin"
mailman.PopPassword = "myPassword"

Dim bundle As Chilkat.EmailBundle
'  Copy the all email from the user's POP3 mailbox
'  into a bundle object.  The email remains on the server.
'  (There are other methods for deleting email from a POP3 server.)
bundle = mailman.CopyMail()

If (bundle Is Nothing ) Then
    MsgBox(mailman.LastErrorText)
    Exit Sub
End If


Dim i As Long
Dim email As Chilkat.Email
For i = 0 To bundle.MessageCount - 1
    email = bundle.GetEmail(i)




    success = bounce.ExamineEmail(email)
    If (success = false) Then
        MsgBox(bounce.LastErrorText)
        Exit Sub
    End If


    If (bounce.BounceType = 1) Then
        '  Hard bounce, log the email address
        TextBox1.Text = TextBox1.Text & "Hard Bounce: " _
             & bounce.BounceAddress & vbCrLf
    End If

    If (bounce.BounceType = 2) Then
        '  Soft bounce, log the email address
        TextBox1.Text = TextBox1.Text & "Soft Bounce: " _
             & bounce.BounceAddress & vbCrLf
    End If

    If (bounce.BounceType = 3) Then
        '  General bounce, no email address available.
        TextBox1.Text = TextBox1.Text & "General Bounce: No email address" & vbCrLf
    End If

    If (bounce.BounceType = 4) Then
        '  General bounce, log the email address
        TextBox1.Text = TextBox1.Text & "General Bounce: " _
             & bounce.BounceAddress & vbCrLf
    End If

    If (bounce.BounceType = 5) Then
        '  Mail blocked, log the email address
        '  A bounce occured because the sender was blocked.
        TextBox1.Text = TextBox1.Text & "Mail Blocked: " _
             & bounce.BounceAddress & vbCrLf
    End If

    If (bounce.BounceType = 6) Then
        '  Auto-reply, log the email address
        TextBox1.Text = TextBox1.Text & "Auto-Reply: " _
             & bounce.BounceAddress & vbCrLf
    End If

    If (bounce.BounceType = 7) Then
        '  Transient (recoverable) Failure, log the email address
        TextBox1.Text = TextBox1.Text & "Transient Failure: " _
             & bounce.BounceAddress & vbCrLf
    End If

    If (bounce.BounceType = 8) Then
        '  Subscribe request, log the email address
        TextBox1.Text = TextBox1.Text & "Subscribe Request: " _
             & bounce.BounceAddress & vbCrLf
    End If

    If (bounce.BounceType = 9) Then
        '  Unsubscribe Request, log the email address
        TextBox1.Text = TextBox1.Text & "Unsubscribe Request: " _
             & bounce.BounceAddress & vbCrLf
    End If

    If (bounce.BounceType = 10) Then
        '  Virus Notification, log the email address
        TextBox1.Text = TextBox1.Text & "Virus Notification: " _
             & bounce.BounceAddress & vbCrLf
    End If

    If (bounce.BounceType = 11) Then
        '  Suspected bounce.
        '  This should be rare.  It indicates that the Bounce
        '  component found strong evidence that this is a bounced
        '  email, but couldn't quite recognize everything it
        '  needed to be 100% sure.  Feel free to notify
        '  support@chilkatsoft.com regarding emails having this
        '  bounce type.
        TextBox1.Text = TextBox1.Text & "Suspected Bounce!" & vbCrLf
    End If

    If (bounce.BounceType = 12) Then
        '  Challenge/Response - Auto-reply message sent by SPAM software
        '  where only verified email addresses are accepted.
        TextBox1.Text = TextBox1.Text & "Challenge: " _
             & bounce.BounceAddress & vbCrLf
    End If

    If (bounce.BounceType = 13) Then
        '  Address Change Notification Message.
        TextBox1.Text = TextBox1.Text & "Address Change: " _
             & bounce.BounceAddress & vbCrLf
    End If

    If (bounce.BounceType = 14) Then
        '  Success DSN indicating that the message was successfully relayed.
        TextBox1.Text = TextBox1.Text & "DSN Successful Relay: " & vbCrLf
    End If



Next



mailman.Pop3EndSession()