A new tweak in the Cydia app store will allow you to add the pull-to-refresh feature to the iPhone’s native, default mail.app. This addictive feature was made popular by many Twitter apps, including the official client. By pulling the screen down as far as possible without scrolling, you can trigger a quick refresh of your inbox.
The Pull To Refresh for Mail tweak is available now for your jailbroken iOS device of choice and requires mobilesubstrate and firmware 3.x or iOS 4. You can download it now from the BigBoss repository in Cydia. A brief video of the tweak in action below: