On Symantec Messaging Gateway (SMG) Control Center, you find Enable password reset feature in the Administrators page. You want to know how this feature works.

When enabled and saved, Enable password reset checkbox will show you Forget your password? link in the logon page, if and only if you entered a bad password for the registered administrators account. 

By clicking this link you'll see the following page where you can enter the user name whose password needs to be reset.