Hi Mark,
I am not sure why this doesn’t work in your environment, but on my server, as an admin, I can go to:
Preferences
eMail / Preferences
Forced preferences TAB
Scroll down to "Folder settings"
The first item there is “Trash folder”. I set that to “/Trash”
I think you will need to have an appropriately named folder in your own mailbox to set a name. So, if your admin does not even have a mailbox, it proably won’t work…
Otherwise, this should be working fine.
Andre