iPhone IPad email

Both your iPad and iPhone require an Internet connection and a connection to the mail server, as the mail server has the master copy of all email. When you delete from one device a request is sent to the server to delete it from the server (or more correctly, move it to the deleted folder). The next time the server syncs to other devices it will be deleted on those devices. This doesn’t always happen in real time, except for iCloud and MS Exchange accounts that support Push technology. You can control how often the sync takes place in your Mail settings.