Official Gmail Blog: Important changes to email deletion on the iPhone mail client
next time when you sync you iPhone with itunes,
it will be updated with new version of apple software.
IPhone mail app will now use IMAP to access Gmail account instead POP as a result it keeps your mail sync
what happens, when you read a message in you iPhone it will be marked as read in Gmail.
if you delete a message on your iPhone it will be moved to trash in Gmail.
