(Credit: Apple)One of the oddest things I have encountered while using my new iPhone 4 running iOS 4 is the occasional blank e-mail message or lack of message preview in Mail. A few simple steps can help alleviate the issue and have you back to your normal message-reading sanity.
After setting up a new account on your iOS 4 device, you may find that the Mail App will not load message previews or show that you have a message from "(No Sender)."
First, be sure message previews are enabled for each of your Mail accounts. Navigate to Settings > Mail, Contacts, Calendars > Preview. If the preview setting is set to "None" change the value to the desired amount of preview lines.
(Credit: Apple)If your preview settings are set to show previews but you're not seeing them in Mail, follow these steps:
- Quit and reopen Mail.
- Double-click the Home button to bring up the multitasking dock. Tap and hold the Mail icon until the red minus sign appears.
- Tap the red minus button to quit Mail and remove it from the recently used Apps list.
- Double-click the Home button to return to your start screen and reopen the Mail App.
source : http://reviews.cnet.com/8301-19512_7-20013895-233.html