How do you produce a report to show which users visited a particular web site on a Sophos UTM 9 Proxy? (VM) (9.501-5)

For example: I would like a list of users who have accessed web mail 

Also, time stamped, duration, traffic etc

Also, time stamped, duration, traffic etc

Not sure why you want this information, Andy, so I can't tell if you would find what you need on the 'Web Usage Report' tab in 'Logging & Reporting >> Web Protection'.  Press on the green + to select 'Site'.  If that doesn't provide enough information, take a look at the companion iView product.

Cheers - Bob