email - Is there a way in Mozilla Thunderbird to delete mail from the remote server and keep it locally?

Is it possible to have Thunderbird delete mail from the server but leave it on your local disk?

Ideally I'd like to be able set it up so that it will delete mail on the remote server under a certain number of days but keep it locally so I can reference it if need be.

What would be even more awesome if I could set different policies on different folders, so that certain email gets cleanup more often then other email.