Have you ever think that what happens when you hit the “Send” button after writing the mail to anyone. The mail instantly appears on recipient email inbox. But there are lots of process happened before that. Google released an official video helping you to understand how Gmail works. Also there is an HTML version of this video known as Storyofsend.
In video it is illustrated that when you hit “Send” button, mail travel through cable or DSL lines through infrastructure and reaches to Google’s data center by passing through various security checks. It then enters into networking room and then routed to Gmail servers. Servers process that mail and make a duplicate copy in the form of backup.
Check out the video: