Notifications: Checkmark this setting to allow your phone to receive a notification in the Status Bar whenever you receive a new message.
Preview: Checkmark to preview message contents when a new message is received.
New message popup: Checkmark to show a popup when new messages are received.
Notification sound: Allows you to select the ringtone to sound when you receive a new message notification.
Vibrate: Allows you to to set the phone vibration setting when you receive a new message notification.
Message Reminder: Checkmark to be reminded of unread messages every 2 minutes.