Set time out to avoid infinite hang when SMTP servers don't respond in time.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@18959 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/tasks/Mailer.java

@@ -231,6 +231,11 @@ public class Mailer extends Notifier {
 			}
             if(getSmtpAuthUserName()!=null)
                 props.put("mail.smtp.auth","true");
+
+            // avoid hang by setting some timeout. 
+            props.put("mail.smtp.timeout","60000");
+            props.put("mail.smtp.connectiontimeout","60000");
+
             return Session.getInstance(props,getAuthenticator());
         }