currently there is no way to manage this from admin panel. All out going mail send through the email@example.com address.
How ever u can follow following step to solve this issue
1.find components/com_google/controller.php - from fron end
2.see line no 46 - $from ="info@".$_SERVER['HTTP_HOST'];
3. change it as per your desire
if u have any ques ple comment here
new release can change 'from Email address'