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.
Performing these steps resets all system settings (e.g., ringtones, sound settings, display settings, etc.) back to their default values. Personal data such as downloaded apps and media (pictures, videos, music) are not affected.
From a Home screen, navigate: Apps icon > Settings > Backup & reset.
Tap Network settings reset.
Tap Reset settings.
If presented, enter login credentials (e.g., PIN, Password, etc.).