An iPhone OS 3.0 security flaw which lets you read deleted emails has been found by Matt Janssen.
The bug was discovered when searching for email using the new Spotlight feature. Janssen noticed that emails he had already deleted were listed in the search results.
On the first attempt to open the deleted email the iPhone will crash; however, a second attempt opens the entire deleted message.
iClarified - Apple News - iPhone OS 3.0 Security Flaw Lets You Read Deleted Emails