fixes #2325

app/models/dmail_filter.rb

@@ -11,7 +11,11 @@ class DmailFilter < ActiveRecord::Base
   end
 
   def filtered?(dmail)
-    dmail.from.level <= User::Levels::MODERATOR && (dmail.body =~ regexp || dmail.subject =~ regexp)
+    dmail.from.level <= User::Levels::MODERATOR && has_filter? && (dmail.body =~ regexp || dmail.subject =~ regexp)
+  end
+
+  def has_filter?
+    !words.strip.empty?
   end
 
   def regexp

test/unit/dmail_test.rb

@@ -31,6 +31,16 @@ class DmailTest < ActiveSupport::TestCase
         @dmail.save
         assert(@dmail.is_deleted)
       end
+
+      context "that is empty" do
+        setup do
+          @recipient.dmail_filter.update_attributes(:words => "   ")
+        end
+
+        should "not filter everything" do
+          assert(!@recipient.dmail_filter.filtered?(@dmail))
+        end
+      end
     end
 
     context "from a banned user" do