Put into a VBS file, ie sendmail.vbs.
Set emailObj = CreateObject("CDO.Message")
emailObj.From = "cat@gmail.com"
emailObj.To = "cat@gmail.com"
emailObj.Subject = "Test CDO"
emailObj.TextBody = "Test CDO"
emailObj.AddAttachment "c:\windows\win.ini"
Set emailConfig = emailObj.Configuration
emailConfig.Fields("http://schemas.microsoft.com/cdo/configuration/smtpserver") = "smtp.gmail.com"
emailConfig.Fields("http://schemas.microsoft.com/cdo/configuration/smtpserverport") = 465
emailConfig.Fields("http://schemas.microsoft.com/cdo/configuration/sendusing") = 2
emailConfig.Fields("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate") = 1
emailConfig.Fields("http://schemas.microsoft.com/cdo/configuration/smtpusessl") = true
emailConfig.Fields("http://schemas.microsoft.com/cdo/configuration/sendusername") = "cat"
emailConfig.Fields("http://schemas.microsoft.com/cdo/configuration/sendpassword") = "Ccat1"
emailConfig.Fields.Update
emailObj.Send
If err.number = 0 then Msgbox "Done"
At Google's web site for GMail you have to turn this feature on for CDO to work.
At your Gmail page click Settings - Accounts and Import - Other Google Account Settings - [At very bottom of page] Allow less secure apps.
Also from memory you also have to click a link in an email the first time you use it (it's been a few years).