Nice Step Found try it.

Open and login to the SEPM

Click Monitors

Click Notifications

Click Notification Conditions

Click Add

Select Client security alert

check out the required option(Device Control events) under "What settings would you like for this notification?"

Set the notifcation condition

Then Add your email id here.

Then Ok

This process will help to get the Device acess log in Email

https://www-secure.symantec.com/connect/forums/not...

Hello,

Solution

1. Log in to Symantec Endpoint Protection Manager Console (SEPM)
2. Click Policies on the left menu, then click Application and Device Control in the View Policies pane.
3. Edit or create a new application policy:
   
   1. Click Application Control in the left pane of the policy.
   2. In the right pane, enable Log files written to USB drives.
4. Click the edit button to modify the Log Files written to USB drives policy configuration.
5. Click Log writing to USB drives under Log files written to USB drives, in the left pane,
6. Under the Properties tab, select asterisk (*) from the Apply to the following files and folders and click on Edit...
7. Confirm the USB device (USBSTOR*) is defined under Only match files on the following device id type and click OK
8. Under the Actions tab, if you want to log the read, create, delete or write attempt to USB device, please check Enable logging.
9. Click OK twice.
10. Assign this policy to groups

How to view the Logs for the USB Activities:

1. Log in to the SEPM.
2. Click Monitors on the left menu.
3. Click the Logs tab.
4. Choose Application and Device Control as log type.
5. Choose Application Control as log content.
6. Select the appropriate time range and click the View Log button.

Note: You can find the same information from database table "DBA.AGENT_BEHAVIOR_LOG_2"

Check this Article:

Policy to LOG activity in a USB drive by Symantec Endpoint Protection

http://www.symantec.com/business/support/index?page=content&id=TECH155578

Check this Thread with similar Issue - 

https://www-secure.symantec.com/connect/forums/view-files-written-usb

Hope that helps!!