You can do it with below.
Add below code in your app/code/local/Vendor/Module/etc/config.xml
<?xml version="1.0"?>
<config>
<modules>
<Vendor_Module>
<version>0.1.0</version>
</Vendor_Module>
</modules>
<global>
<blocks>
<module>
<class>Vendor_Mo...
how can i add mail id on sales order grid
this is the complete code which you gave last
<?php class Vendor_Module_Block_Adminhtml_Sales_Order_Grid extends Mage_Adminhtml_Block_Sales_Order_Grid { protected function _prepareCollection() {