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).