In iPhone OS 3.0, the act of deleting an email doesn’t necessarily mean it is immediately gone forever, it’s actually cached for a while.
Matt Janssen created a YouTube video that demonstrates deleted messages can be retrieved via a simple Spotlight search on your iPhone or iPod touch. Janssen claims he has found emails from three to four months ago using this method. Don’t believe it? Try it out for yourself.
You can test the flaw by creating an email message with a memorable subject (just so it’s easier to find), and then delete it. Go to your Trash and remove it from there as well. Check your mail server (IMAP and POP both work) to ensure you have completely erased it. Then, go to Spotlight and search for your memorable subject. Your search results should show the message and in many cases, the entire message itself.
The messages do eventually disappear, but there is just no telling when. There have been reports of simple workarounds, like viewing the deleted message three to four times, but this method would be overly tedious if you want to ensure every single message is completely removed from your device. According to Gizmodo, Apple is aware of the issue and will hopefully be including a fix in the official release of iPhone OS 3.1.
[via Cult of Mac]