Object variable or With block .... sending e-mail CDO

Hi,

on one forum I found a maco to send e-mail but it doesn't work. I get an error "Run-time 91 Object variable or With block variable not set"
How can I fix it ?

Thanks for any help !

Sub Send_Margins()
  Dim cdoConfig
  Dim msgOne
  Dim MI As Object
  
  
  MI = Dir("C:\Users\Desktop\myfile.xlsm")

  Set cdoConfig = CreateObject("CDO.Configuration")
    With cdoConfig.Fields
      .Item("http://schemas.microsoft.com/cdo/configuration/sendusing") = 2
      .Item("http://schemas.microsoft.com/cdo/configuration/smtpserver") = "name of my SMTP server"
      .Item("http://schemas.microsoft.com/cdo/configuration/smtpserverport") = 25
      .Update
    End With

  Set msgOne = CreateObject("CDO.Message")
  Set msgOne.Configuration = cdoConfig
    msgOne.To = "[email protected]"
    msgOne.CC = ""
    msgOne.From = "[email protected]"
    msgOne.Subject = "hello"
    msgOne.TextBody = "test test test"
    msgOne.AddAttachment "C:\Users\Desktop\myfile.xlsm"

    msgOne.Send

End Sub