caching message list

So I generally read lists with tons of messages in them. When I load 
them, it takes quite some time to read all of the messages form the 
server (a minute or two.) Is there a way to cache them, the way that 
Thunderbird does? I'm a new tin user, and it seems that it should only 
have to download new headers, but it seems like it redownload all of the 
headers every time that I restart tin.