Hi @Karun Khanna ,
Your second plan is better, it should be noted that if you use "OR" to connect the second group of keywords, as long as the email contains any keyword, it will not be displayed in the results. If you use the "AND" connection, then only if the email contains all keywords at the same time, it will not be displayed in the results. As my test results, if an email contains both keywords that need to exist and keywords that do not need to exist, the email will not appear in the search results.
The screenshot below is test in my lab environment, tested the results returned by using "OR" and "AND" to connect the second set of keywords, which hope can help you understand better.
The mail in my mailbox.
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