If you can't connect to the internet, send or receive email and/or messages (text, picture or video), resetting the network settings may help.
The following are cleared or restored to default values:
Cellular and Wi-Fi network settings (including saved networks and passwords)
From a Home screen, navigate: Settings > System > Reset.
If there are multiple tabs to choose from in Settings, tap on the Menu icon (located in the upper-right) and tap List view.
These instructions apply to Standard mode only.