====== Remove a dead Exchange server from Active Directory ======
  * Connect to the domain controler
  * Launch the run dialog (Windows Key + R)
  * Type in the command “adsiedit.msc” et then press “OK”
  * Right click on the console then “Connect to:”
  * In the connexion dialog select “Well known Naming Context”
  * In the drop down menu select “Configuration”
  * Explode “CN=Configuration [domain]\CN=Services\CN=Microsoft Exchange\CN=[organization]\CN=Administrative Groups\CN=Servers”
  * Right click on the dead server and pick “Delete”
  * We also need to delete Database information as well, navigate to “CN=Configuration [domain]\CN=Services\CN=Microsoft Exchange\CN=[organization]\CN=Administrative Groups\CN=Databases”
  * Explode each items to find wich one is related to the old server, then delete it as well.