You can have your Lotus Notes mail box locked if you have left it unused for a specific preset time. This will ensure that your mails are safe and not opened by others even if you are away from your desk for a long time.

To have this feature enabled follow the steps below.

1. Log into your Lotus Notes account and go to File - Preferences - User Preferences.
2. In the Basics view, at the bottom of the view an option to logout and lock Lotus Notes if unused for the specific time is available. Enable it.
3. There is another box to set the duration after which Notes is to be locked if unused. Select the duration according to your requirement.
4. Save your preferences and you will find that Notes will be locked after the preset time, if left unused.