dopo aver autenticato un utente, gli faccio scaricare un file pdf..la procedura funziona, solo che, se metto il blocco di gestione delle eccezioni, dopo che mi sono inviato una mail per comunicarmi che è avvenuto un errore, faccio il redirect dell'utente ad una pagian errore
questo è il codice:

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Try
Dim path As String = Server.MapPath("../mdb-database/listini/" & Request("ID") & ".pdf")
Dim file As New FileInfo(path)


Response.Clear()
Response.AddHeader("Content-Disposition", "attachment; filename=" & Request("ID") & ".pdf")
Response.AddHeader("Content-Length", file.Length.ToString())

Response.ContentType = "application/pdf"
Response.WriteFile(file.FullName)
Response.End()
Catch ex As Exception

Dim mailNew As New System.Web.Mail.MailMessage
mailNew.From = "info@lansec.it"
mailNew.To = "info@castaweb.it"
mailNew.Subject = "Sito lansec-errore"
mailNew.Body = "IDUtente: "
If Request.IsAuthenticated = True Then
mailNew.Body = mailNew.Body & Request.Cookies("lansec")("IDUtente")
End If
mailNew.Body = mailNew.Body & vbCrLf
mailNew.Body = mailNew.Body & vbCrLf
mailNew.Body = mailNew.Body & vbCrLf
mailNew.Body = mailNew.Body & "pagina:"
mailNew.Body = mailNew.Body & vbCrLf
mailNew.Body = mailNew.Body & vbCrLf
mailNew.Body = mailNew.Body & Request.ServerVariables("query_string")
mailNew.Body = mailNew.Body & vbCrLf
mailNew.Body = mailNew.Body & vbCrLf
mailNew.Body = mailNew.Body & "REMOTE_ADDR: " & Request.ServerVariables("REMOTE_ADDR")
mailNew.Body = mailNew.Body & vbCrLf
mailNew.Body = mailNew.Body & "REMOTE_HOST: " & Request.ServerVariables("REMOTE_HOST")
mailNew.Body = mailNew.Body & vbCrLf
mailNew.Body = mailNew.Body & vbCrLf
mailNew.Body = mailNew.Body & ex.ToString
mailNew.Fields("http://schemas.microsoft.com/cdo/configuration/sendusing") = ConfigurationSettings.AppSettings("sendusing")
mailNew.Fields("http://schemas.microsoft.com/cdo/configuration/smtpserver") = ConfigurationSettings.AppSettings("smtpserver")
mailNew.Fields("http://schemas.microsoft.com/cdo/configuration/smtpserverport") = ConfigurationSettings.AppSettings("smtpserverport")
mailNew.Fields("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate") = ConfigurationSettings.AppSettings("smtpauthenticate") '
mailNew.Fields("http://schemas.microsoft.com/cdo/configuration/sendusername") = ConfigurationSettings.AppSettings("sendusername")
mailNew.Fields("http://schemas.microsoft.com/cdo/configuration/sendpassword") = ConfigurationSettings.AppSettings("sendpassword")
SmtpMail.SmtpServer = ConfigurationSettings.AppSettings("smtpserver")
SmtpMail.Send(mailNew)



End Try

funziona solo che, se alla fine aggiungo un redirect alla pagina errore, ottengo un errore.....

esatto!

e il redirect è questo:
Response.Redirect("errore.aspx?err=2", False)