So, it's important to note, that you can use the When an email is deleted Trigger on a person's mailbox. The issue is, you have to have admin privileges to do this because you have to have access TO their mailbox to monitor it.
Also, if you use flows you need one for every single mailbox you want to monitor.
There are other ways but no matter how you need access, and then you would have to track how many they delete because.
1) what if they delete 1, then another then another then another. They didn't mass delete at once, they deleted 1 at a time really fast... and the flow would trigger each time, so you'd have to track somewhere.
Also, if you have access to their emails there is the option to run the flow and save it somewhere
Lastly, let me say, if you are trying to stop people, an Admin of course can always restore them.
But if you wanted this at the organization level this will be really really really hard using this platform, you would want to use more things like PowerShell, Admin Tools etc.
If these suggestions help resolve your issue, Please consider Marking the answer as such and also maybe a like.
Thank you!
Sincerely, Michael Gernaey
