After the iphone5 upgrade to iOS7, you will find that this situation is greatly improved, and you can do various things with the content of the message on the list page of the message, including setting all unread messages to read.
To set the Read method for a single unread message:
1. Click on the mobile desktop "mail" icon.
2. After opening the mailbox, in the Inbox of the mailing list interface, from right to left gently slide the title of a message, there will be "delete" and "more" two button icons, select "More" this option.
3. A new window will pop up about half a screen. There are a lot of specific actions on this message, such as: reply, forwarding, flag, marked unread, move to the spam box, mobile mail, etc., select the "Mark as unread" option, the message becomes read state.
All set as Read mail:
1. Click on the desktop "mail" icon entrance.
2. There is an "edit" button in the upper right corner of the message display interface, and when clicked, the icon appears in the bottom right of the screen and selects it.
3. At this time the screen interface will appear "flag", "marked as read" These two options, click "Marked as read", all the messages have become read state.