add py3k warnings to  rfc822
diff --git a/Lib/rfc822.py b/Lib/rfc822.py
index 14cc729..4382a51 100644
--- a/Lib/rfc822.py
+++ b/Lib/rfc822.py
@@ -73,6 +73,9 @@
 
 import time
 
+from warnings import warnpy3k
+warnpy3k("in 3.x, rfc822 has been removed in favor of the email package")
+
 __all__ = ["Message","AddressList","parsedate","parsedate_tz","mktime_tz"]
 
 _blanklines = ('\r\n', '\n')            # Optimization for islast()