Sony Ericsson Xperia X10 Mini/pro :: Email App Loads All Emails As Unread

I have set up the Email app on the phone to connect to my Yahoo! Mail account. However, the Email app always regards incoming messages as unread even if they have already been marked as read on the Yahoo! Mail account itself. This makes the unread messages count in the Email app inaccurate and unhelpful.

The Email app does not appear to possess a facility to mark several messages as read, the only way to bring the unread count down is to open each message in turn. Sometimes a message has to be opened twice in the app before it is regarded as read. I can delete more than one message on the phone, but this also deletes the messages on the Yahoo! Mail account, which is not what I want.

I have tried deleting the email account from the Email app and then reinstating it, but I now have an unread message count of 50 on the phone when all of these messages have, in fact, already been read on the Yahoo! Mail account.

I can also access the Yahoo! Mail account by means of the Yahoo! Mail app on the phone, but one of the disadvantages of this is that the icon for Yahoo! Mail does not possess an unread messages count at all.