I have my iPhone sync'd with my .Mac account. It synced several hundred emails tht I had already read.. so instead of deleting them one by one on the iphone, delete the in masses on the computer (Using Mail.app in my case) and then get mail with the iphone and all those massages are gone.
Probably a commen sense thing, but hey, sometimes it escapes us.
Probably a commen sense thing, but hey, sometimes it escapes us.