Syntax: override on|off
The override command is useful when looking at or modifying
databases other than an alias database. Ordinarily the database
manipulation commands, add, copy, modify, rename, remove, set,
and show will only operate on aliases with the mail-address
attribute. When the command "override on" has been issued, these
commands can be used to manipulate any entry in the database
regardless of its attributes (or lack thereof).
The "override off" command negates the "override on" command.