impl sender watcher and queue

mail/mail.go

@@ -23,18 +23,19 @@ func NewEmail(sender string, receivers []string, subject, content string) Email
 	}
 }
 
-func FromJSON(path string) error {
+func FromJSON(path string) (Email, error) {
+	var mail Email
+
 	content, err := ioutil.ReadFile(path)
 	if err != nil {
-		return err
+		return mail, err
 	}
 
-	var mail Email
 	if err := json.Unmarshal(content, &mail); err != nil {
-		return err
+		return mail, err
 	}
 
-	return nil
+	return mail, nil
 }
 
 func (e Email) Generate() []byte {