diff -r 9cccfaa6b534 Lib/test/test_smtpd.py
--- a/Lib/test/test_smtpd.py	Mon Mar 12 22:59:49 2012 +0100
+++ b/Lib/test/test_smtpd.py	Tue Mar 13 07:32:36 2012 +0900
@@ -166,6 +166,11 @@
         self.assertEqual(self.channel.socket.last,
             b'503 Error: nested MAIL command\r\n')
 
+    def test_HELO_EHLO_before_mail_transaction(self):
+        self.write_line(b'MAIL from:<foo@example.com>')
+        self.assertEqual(self.channel.socket.last,
+                         b'503 Bad sequence of commands')
+
     def test_need_RCPT(self):
         self.write_line(b'MAIL From:eggs@example')
         self.write_line(b'DATA')