use managed attribute

email.go

@@ -41,6 +41,10 @@ func (e *Email) Send() error {
 	log.WithFields(log.Fields{}).Debugf("starting")
 	defer log.WithFields(log.Fields{}).Debugf("done")
 
+	if len(e.items) == 0 {
+		return nil
+	}
+
 	body := " - " + e.items[0]
 	for _, item := range e.items[1:] {
 		body = body + "\r\n" + item