Update read emails on lock screen

No, those aren't the e-mails themselves, those are notifications telling you about the e-mails.

The Exchange sync system can alter the e-mails themselves, but it can't touch the notifications. The only way to clear those is to unlock the phone.

It's like someone mailed you a physical letter every time you get a phone call at home. Sometimes you answer the phone and sometimes not, but you'll have a letter from every single phone call outside in your mailbox. And there's no way for the phone to empty the box.

 

I use change sync with Google Apps account.

When I read emails on web interface or on iPad, it wipes notifications on iphone lockscreen and notification center. It does work, I always thought that was really cool.