added a test for "To: :" patch
diff --git a/Lib/test/test_rfc822.py b/Lib/test/test_rfc822.py
index 96654f4..0d4c66f 100644
--- a/Lib/test/test_rfc822.py
+++ b/Lib/test/test_rfc822.py
@@ -113,3 +113,10 @@
 
 test''', [('Comment stuff', '"Quoted name"@somewhere.com'),
           ])
+
+test('''To: :
+Cc: goit@lip.com
+Date:    Wed, 13 Jan 1999 23:57:35 -0500
+
+test''', [('', 'goit@lip.com')])
+