The standard e-mail application that comes with the iPod and iPhone suffers from a man in the middle vulnerability due to not validating SSL certificates.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/81459/iphonemail-mitm.txt
Source: https://packetstormsecurity.com/files/81459/iPod-iPhone-E-Mail-Man-In-The-Middle.html