Anyone with a large multisite installation has probably been there before; when you set up a new site, you set yourself as the main administrator just to get through the setup process, but then you want to hand it off to someone else. You go to Settings -> General in the administration area and put the new admin’s email address in there, just to have WordPress remind you that the new admin has to “confirm” before the change actually takes place. This can be extremely frustrating.
If you change the administrator email address through Network Admin, the change goes through immediately without requiring confirmation
However, did you know that you can circumvent this “confirmation” process within multisite? Instead of making the change through Settings -> General, go to your Network Admin area and then to Sites -> All Sites. Find the site you want to update and click the “Edit” button. Then, click on the “Settings” tab. If you change the Admin Email value within that screen, WordPress won’t require the new administrator to confirm their address before the change goes through. The new admin will immediately begin receiving all of the admin notification messages for the site, rather than you getting them dumped into your inbox.