New day, new app in Cydia Store: PopMark. PopMark lets you mark all emails as read with one tap instead of checking them one by one. All you need to do is to tap on the app’s icon, and let it do its magic. The app is compatible with iOS 3.1.x and 4 and only works with POP mail accounts. ( IMAP not supported )
You can buy this app from Cydia Store for $1.99 …