diff --git a/libreplan-webapp/src/main/java/org/libreplan/web/common/ConfigurationController.java b/libreplan-webapp/src/main/java/org/libreplan/web/common/ConfigurationController.java
index 2a8400afc..bd82e3ed7 100644
--- a/libreplan-webapp/src/main/java/org/libreplan/web/common/ConfigurationController.java
+++ b/libreplan-webapp/src/main/java/org/libreplan/web/common/ConfigurationController.java
@@ -49,13 +49,18 @@ import org.zkoss.zk.ui.event.EventListener;
 import org.zkoss.zk.ui.event.Events;
 import org.zkoss.zk.ui.event.SelectEvent;
 import org.zkoss.zk.ui.util.GenericForwardComposer;
+import org.zkoss.zkplus.spring.SpringUtil;
 import org.zkoss.zul.*;
-import org.zkoss.zul.api.Window;
 import org.zkoss.zul.impl.InputElement;
 
+import javax.mail.AuthenticationFailedException;
+import javax.mail.MessagingException;
+import javax.mail.Session;
+import javax.mail.Transport;
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
 import javax.ws.rs.core.Response.Status;
+import java.io.*;
 import java.util.*;
 
 import static org.libreplan.web.I18nHelper._;