outlook.office.com boolean mail searching

This is about (somewhat advanced) searching in the online outlook mail client at outlook.office.com. Our office uses this as a corporate service and I am accessing it off-premises in a browser from a 3rd party computer via vpn connection. I pretty much only ant to touch the inbox and user searching/filtering to pull the few interesting mails from hundreds of in-house aliases. At the top of the page near the 'Outlook' brand-logo is the search/filter field. What is the syntax for some Boolean filtering in that input field? Most of the non-interesting emails are from corporate aliases that are all called 'ask_expert_***' So I tried entering "NOT expert". That seems to have eliminated a bulk of the emails from the displayed list. So what is the (reasonably) full syntax spec for filtering that can be performed in this field? Using AND/OR/NOT and parentheses ??? Thanks, Gert.

This should hopefully give you an idea of the search criteria available:

https://support.office.com/en-us/article/Learn-to-narrow-your-search-criteria-for-better-searches-in-Outlook-d824d1e9-a255-4c8a-8553-276fb895a8da