Valid for Alpha and Integrity server systems only.
    Creates a virtual mailbox named MBAn and assigns an I/O channel
    number to it. The /MAILBOX qualifier is required.
                                   NOTE
       The following privileges are required:
       o  TMPMBX (temporary mailbox) to create a temporary mailbox
          (which is the default)
       o  CMEXEC (change mode to executive) to create a temporary
          mailbox (which is the default). Note: This requirement is
          temporary and will be removed in a future release.
       o  PRMMBX (permanent mailbox) to create a permanent mailbox
          (using the /PERMANENT qualifier)
       o  SYSNAM (system logical name) to place a logical name for
          a mailbox in the system logical name table
       o  GRPNAM (group logical name) to place a logical name for a
          mailbox in the group logical name table
    To delete a mailbox, use the DELETE/MAILBOX command.
    Format
      CREATE/MAILBOX  logical-name
Additional Information:
explode
extract