From Forum Nokia Wiki

ID	TSS000552	Creation date	December 29, 2006
Platform	S60 3rd Edition, Enterprise Solutions SDK Plugin	Devices	Nokia E61
Category	Symbian C++	Subcategory	Messaging, E-mail

Keywords (APIs, classes, methods, functions):

Overview

Controlling LED on Nokia E61 for incoming messages

Description

The LED on the front panel of the Nokia E61 flashes to announce the arrival of new messages. This can also be controlled using Publish & Subscribe keys.
Solution:
    // iProperty is of type RProperty
    iProperty.Attach( KPropertyUidEmailLedCategory, KEmailLEDOnRequest );
    iProperty.Subscribe( iStatus ); // subscribe to LED status changes (using an active object)
    // to switch on LED blinking
    iProperty.Set( 1 );
    // to switch off LED blinking
    iProperty.Set( 0 );
KPropertyUidEmailLedCategory and KEmailLEDOnRequest UIDs are defined in the emailledvalues.h header in the Enterprise Solutions SDK.
The Enterprise Solutions SDK is available only in Forum Nokia PRO.