I'm on 1.1.3 and have a Yahoo email account that I kept the emails on the server so that I can access it anywhere. The problem is the iPhone keeps all the downloaded emails in var/mobile/Library/Mail/ even after I deleted them on the iPhone.. If I SSH in and maunaully delete them, the next time I open up mail, it will starts downloading them all over again.

This is becoming a problem for me since it's over 300mb right now and keeps on building... I have the option to remove deleted messages after one day checked, but it really doesn't remove them from the storage in var/mobile/Library/Mail/ Is there any way I can remove the messages?? Shouldn't there be a cache file to let the iPhone knows which email has been downloaded before etc instead of actually keeping all the downloaded emails?