At a minimum, set AUTORUN_SCHEDULE and NOTIFICATION_EMAIL.
For example, to set the tool to run at 3 AM every Sunday and email the results to some.body@example.com, run the following command:
$ ./orachk –set “AUTORUN_SCHEDULE=3 * * 0 ;NOTIFICATION_EMAIL=some.body@example.com”
$ ./exachk –set “AUTORUN_SCHEDULE=3 * * 0 ;NOTIFICATION_EMAIL=some.body@example.com”