Go to Control Panel and click on View View 32-bit Control Panel Items and after that you can see the Mail Icon.
If still you are not able to see the Mail Icon or you are using Windows Vista 32-Bits, then the Outlook is not set as default program for e-mail. To set the Outlook as default email program, do the following steps: -
Go to Control Panel,
Click on View Classic Icons
Click on Set Default Programs
Select the Microsoft Office Outlook in the list in left side.