Hi Guys,, Please help me to answer this question.

If your boss comes to you with an email that is showing up every two minutes saying the, “Oracle Database is running fine, ” from: Linux1@systems.com and he asks you to turn off the this email message,

how would you determine what Linux automation service/script is causing this?
What message should your boss be receiving instead?

First thing I would do is to ask my boss for the full headers on the email he got. (Not just the To and From seen at the top of email and NOT the headers of any email he forwarded to you but the actual headers he got.) Having upper case user names is unusual so the real user probably shows up in the headers.

Assuming Linux1 is really the user:
As root "crontab -l -u Linux1".

It's also possible whatever job is running it is not the user listed so you might check root's cron and Oracle's cron. (All this assumes you're not running a 3rd party scheduling tool.) It is also possible you have cron (or 3rd party scheduling tool) kicking off on a different server and making the connection to the one that is sending the email. That would take additional research.

Also Oracle has concurrent manager scheduling built in so you might check that. I don't manage that scheduling so can't tell you how to check it.

You can check /var/log/maillog to see if you see the email being sent there but often enough (especially with concurrent manager requests or Oracle itself) the mail is being routed directly to your internal mail server via SMTP or IMAP so doesn't show up in the Linux server's maillog as it didn't use whatever MTA the server has installed.

How would we know that?
Ask "The Boss"