Mail - Read / Undrea

Hi, when i receive new emails into my account in Mail, they are marked with the blue unread to signify that they are unread.

When i single click on the new email, the message in marked as read and the content of the email loads in right...

Is there a way to keep the email as unread until you double click the email or carry out some other action to signify that the email is now "read"... thanks in advance...