cannot create mailbox

  Explanation:  An error occurred during an attempt  to  create  a
  mailbox.   Mailboxes  are used for interprocess communication by
  the database management system on VMS.

  User Action:  Examine the secondary messages  to  determine  the
  reason for the failure.  Usually, you will have to change one of
  your quotas (most likely, the buffered I/O byte count  quota  or
  the open file quota).