In order to block any unwanted chat from another player, tap the username of the offending player while in Global Chat.



This will open a Player Info Tab. To block the player, tap on the "Ignore" button and tap "OK" to confirm the action.



Additionally, you can also block unwanted emails by tapping the block button on the bottom right hand corner of your Mail.

To unblock a player, open your Chat and tap on the upper middle button that looks like this:



This will take you to your "User Settings", where you can manage your Mail Block List and Chat Ignore List. Remember that all ignore and block requests are permanent unless they are removed from these lists.