The Version property returns the version number of CDO as a string, for example "1.2". Read-only.
objSession.Version
String
The version number for CDO is represented by a string in the form N.k, where N represents a major version number and k represents a minor version number.
The version number returned in the Version property is not related to the version number returned in the OperatingSystem property.
' see the function Session_Version
Dim objSession As Object ' or Dim objSession As MAPI.Session
Set objSession = CreateObject("MAPI.Session")
' error handling here ...
MsgBox "Welcome to CDO version " _
& objSession.Version