Workaround for missing "remove email from server when deleted" setting?

The workflow in a client's office requires that several users have total access to each of several e-mail accounts. In their desktop Entourage clients I have the settings at "delete from server after 30 days", and "remove from server when deleted". All is well on the desktops.

The boss just got an iPhone (yea!). I have that set to "Delete from server -- Never". Everything is working great - except for spam...and there's a lot of spam. When traveling she uses the iPhone in lieu of a laptop, and feels the need to delete the spam as it clutters the Inbox excessively. Her desktop Entourage does not automatically download e-mails on a scheduled basis - she prefers to manually click Send/Receive. Unfortunately the spam e-mails deleted on the iPhone are still on the server - and download to Entourage when she returns to the office and clicks Send/Receive. And must be deleted again...

So, the only possibility I see is "delete from server -- when removed from Inbox". The trade-off is she wouldn't be able to organize e-mail into folders on the iPhone. Is there any other work-around?

Thanks