You will need to make sure that the Directory Server parameters are correctly specified prior to enabling the Messenger Express Multiplexor. To determine your LDAP parameters, run the following command in the appropriate back-end Messaging Server instance directory:
configutil -o local.ugldaphost
This parameter displays the users and groups LDAP Directory Server that the back-end messaging servers use. Make sure that ldaphost is set to the same value (or a replicated LDAP server containing the same data) that the back-end messaging servers use.
configutil -o local.ugldapbinddn and configutil -o local.ugldapbindcred
These parameters display the DN and password of the users and groups Directory Server administrator. Both ldapbinddn and ldapbindcred must be the same as in your back-end messaging servers specifications.