OS X Mavericks has a new feature that shows notifications from apps such as Mail, Remainder, Messages, FaceTime etc. These notifications by default gets displayed even when the screen is locked. But you can disable showing notifications on the locked screen using the Notification options under System Preferences. Let us see the steps required to turn off notification from Mail App ion lock screen.
Step 1: Click the Apple icon and select System Preferences from menu list.
Step 2: Click the Notifications option under System Preferences screen.
This should display the following Notifications Center Settings screen.
Step 3: Select Mail App option to turn off notifications in lock screen.
Step 4: Now unmark the check box with caption as “Show notifications on lock screen”.
This is quite useful when you do not want others to see any confidential email notifications when you are away from you desk.