update email and stop on error

email.go

@@ -60,7 +60,8 @@ func SendMail(addr, from, subject, body string, to []string) error {
 		return err
 	}
 
-	msg := "To: " + strings.Join(to, ",") + "\r\n" +
+	msg := "Date:" + time.Now().Format("Mon, 02 Jan 2006 15:04:05 -0700") + "\r\n" +
+		"To: " + strings.Join(to, ",") + "\r\n" +
 		"From: " + from + "\r\n" +
 		"Subject: " + subject + "\r\n" +
 		"Content-Type: text/html; charset=\"UTF-8\"\r\n" +