cannot create mailbox

  Explanation:  An error occurred when you attempted to  create  a
  mailbox.   Mailboxes  are used for interprocess communication by
  the database management system.

  User Action:  Examine the associated messages to  determine  the
  reason  for  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).