Imports System.Net.Mail
Imports System.IO.FileInfo
Imports System.IO.File
 
 
Public Class Form3
 
    Dim gesendet As Boolean
    Dim Fileloschen As Boolean
    Dim file As System.IO.File
 
 
    Private Sub Form3_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
 
        BackgroundWorker1.WorkerReportsProgress = True
        BackgroundWorker1.WorkerSupportsCancellation = True
 
    End Sub
 
 
    Sub send()
        Dim Msg As New MailMessage
        Dim myCredentials As New System.Net.NetworkCredential
        Dim file As String = "E:\Test.pdf"
 
        Dim Data As New Attachment(file)
 
 
 
        myCredentials.UserName = "meinusername"
        myCredentials.Password = "******"
 
        Msg.IsBodyHtml = False
 
        Dim mySmtpsvr As New SmtpClient()
 
        mySmtpsvr.EnableSsl = True 'SSL aktivieren
        mySmtpsvr.Host = "smtp.*****.de"
        mySmtpsvr.Port = 25
 
        mySmtpsvr.UseDefaultCredentials = False
        mySmtpsvr.Credentials = myCredentials
 
        Try
            Msg.From = New MailAddress("meine Mailadr")
            Msg.To.Add("empfänger")
            Msg.Subject = "test"
            Msg.Body = "testtext"
            Msg.Attachments.Add(Data)
 
            mySmtpsvr.Send(Msg)
 
        Catch ex As Exception
            MsgBox(Err.Number & ex.Message & ex.StackTrace.ToString) 'Falls  
            ' ein Fehler auftritt wird eine MsgBox angezeigt
        End Try
 
 
    End Sub
 
 
 
 
 
 
    Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e _
      As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
        Timer1.Enabled = False
        Call send()
    End Sub
 
    Private Sub BackgroundWorker1_RunWorkerCompleted(ByVal sender As Object, _
      ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles _
      BackgroundWorker1.RunWorkerCompleted
 
        MessageBox.Show("Email gesendet")
        Timer1.Enabled = True
        Fileloschen = True
 
 
 
    End Sub
 
    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Timer1.Tick
 
#-------------------------------------------------------------------
''Hier kommt der Fehler !!!
 
 
        If Fileloschen = True Then
          file.Delete("E:\VerschlüsselungV1.exe.OLD")
       Fileloschen = False
 
        End If
 
#-------------------------------------------------------------------
 
        If file.Exists("E:\Test.pdf") Then
 
            BackgroundWorker1.RunWorkerAsync()
 
        Else
            MessageBox.Show("KEINE DATEI")
        End If
 
        ' BackgroundWorker1.RunWorkerAsync()
 
 
 
 
 
 
    End SubSy