Help needed, run-time error -2147417851 (80010105)

[Kestis]

Hello, I am trying to excecute this script, but it gives me the following error:
Run-time error -2147417851 (80010105)
Method 'To' of object'_MailItem' failed

What could be the problem? Earlier this script was working without any problems.
I am using Office 2010.

Sub SendMultipleEmails()


  Dim Attach As Object
  Dim myolApp As Object
  Dim Mail As Object
  
    Set myolApp = CreateObject("Outlook.Application")


    For i = 2 To 101
      Set Mail = myolApp.CreateItem(olMailItem)
      Set Attach = Mail.Attachments
        Mail.To = Cells(i, 1)
        Mail.CC = Cells(i, 2)
        Mail.BCC = Cells(i, 3)
        Mail.Subject = Cells(i, 4)
        Mail.Body = Cells(i, 5)
        If Cells(i, 6) <> "" Then
           Attach.Add "" & Cells(i, 6) & ""
        End If
      Mail.send
    Next

 

[Kestis]

As far as I know, it has something to do with OS, everything works fone under Vista (probalby Windows 7) but it does not work under Windows 8.1.
Maybe someone knows what could be the problem?