Here in the image I have pointed to the badge icon.. Do anyone know what this means?
Below is the badge icon from above screenshot..
What do the Outlook icons mean? lists all of the icons in outlook and explains what they mean.
The icon you are referring to is in the Security section and indicates that the message has a Valid Signature:
If you Open the message and then click on this icon you can find more information about the digital signature.
See View a digital signature in a signed e-mail message for more information.
It indicates that the message was digitally signed.