Adding someone to your foes list previously prevented them from sending you trades, it now also stops them from sending you private messages (they'll be told that you have PMs disabled). If you still want to receive PMs from your foes, you can tick the box on your foes list "Allow foes to send me PMs" and save those options.
We now also tell you if you are trying to send a private message to a COPPA'd player, who are unable to read PMs, so they won't have to worry about unreadable PMs sitting in their inboxes .
If you are having problems with another player sending you rude or unwanted PMs please add them to your foe list to prevent them from messaging you.