How long does it take for email forwarding to start working after changing the forwarding address? 

After you finish setting everything up, your emails will start being sent to your new address pretty soon, usually within 10 to 15 minutes.

During this short wait, the system is busy making sure everything is in place so that all your emails go to the right place without any problems. Once this is done, you can be confident that your emails will arrive at the new location quickly and smoothly.