[Dovecot] Does dovecot proxy support message caching?

[Edward Carraro]

For example, say the connection between the user and the dovecot proxy is
fast/cheap, but the connection from the proxy to the dovecot imap backend
server is costly.
is there a way to set up the proxy to cache messages to allow faster
loading? if so, does it have different levels of caching (full message,
headers only, etc)?

I'm using dovecot 2.0.9 for both the proxy and the imap backend.

if not, is there something that can work with dovecot to allow this?

Thanks!