[20-JUN-1991]

The MXU1023.A and B save sets comprise the MX V2.3-1 update.  You must
install MX V2.3 before applying this update.

If you are using the MX SMTP support, you should also obtain (from directory
[ANONYMOUS.NETLIB]) the NETLIB V1.2 installation kit, NETLIB012.A and B, and 
install it after installing MX V2.3 but before applying the MX V2.3-1 update.