We always want our info up to the second!
Microsoft has made a small change to the system which syncs your electronic mail. There's a new setting called "based on your usage" which is the new default for email. In theory it's a handy feature which will learn from your behavior, and tailor how often your phone checks for new messages. However, for many, once an email hits the server we want it on our phone.
Opening an email account, and hitting the three dots at the bottom of your screen will pull up a menu. In that menu hit sync settings, and you'll be able to set timed sync (e.g. every 15 minutes), based on usage, or when items arrive. It's that last one you'll want to select if you want your email to delivery as fast as possible.
Hit the related video to see this tip in action, and where these settings are on your Windows Phone!