Return an empty settings if email is nor valid

git-svn-id: https://svn.apache.org/repos/asf/james/hupa/trunk@1577822 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/server/src/main/java/org/apache/hupa/server/utils/SettingsDiscoverer.java b/server/src/main/java/org/apache/hupa/server/utils/SettingsDiscoverer.java
index 677dfd0..af6724e 100644
--- a/server/src/main/java/org/apache/hupa/server/utils/SettingsDiscoverer.java
+++ b/server/src/main/java/org/apache/hupa/server/utils/SettingsDiscoverer.java
@@ -32,7 +32,13 @@
     @Inject private Provider<Settings> settingsProvider;
 
     public Settings discoverSettings(String email) {
+        
+        if (!email.matches("^(.*<)?[A-Za-z0-9._%'*/=+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,}(>)?\\s*$")) {
+            return new SettingsImpl();
+        }
+        
         String domain = email.replaceFirst("^.*@", "");
+        
         Settings s = validConfigs.get(domain);
         if (s != null) {
             return s;