PowerShell Script

I want to provide a list of UNC network paths. The script needs to access those paths and search for the modified date of the one latest file in each(!) subfolder of that UNC paths. So for each subfolder of each UNC path, there will be always one individual file. If one or more of there files do not change within 30 minutes (they are log files and should change every 5 minutes), I want to get an alert email that says "These files didn't change within 30 minutes: [list of files including paths that didn't change). When an alert was sent, I don't want to receive that alert again for 6 hours.

So the project basically is a PowerShell Script that:
- gets a list of files from given unc paths
- checks their modified date
- alerts by mail if modified date older than 30 minutes
- doesn't alert the same file for 6 hours

Project needs to be finished ASAP.