In the next version of eve, Version 1.2.16, we will be adding support for ignoring users. When you ignore someone, their replies are hidden in topics (you can expand to view them), and you will not receive email notifications when they post new content. In addition, ignored users are not able to send you Private Messages.

Version 1.2.16 is currently in beta testing and should be available in the next 2-3 weeks, barring major issues.

Just an update... Version 1.2.16 was delayed a bit but is back on track and in final beta testing. You should see that release very soon.