Bug #1430298: It is now possible to send a mail with an empty
return address using smtplib.
diff --git a/Lib/smtplib.py b/Lib/smtplib.py
index 57605a9..71d25fd 100755
--- a/Lib/smtplib.py
+++ b/Lib/smtplib.py
@@ -175,8 +175,11 @@
     except AttributeError:
         pass
     if m == (None, None): # Indicates parse failure or AttributeError
-        #something weird here.. punt -ddm
+        # something weird here.. punt -ddm
         return "<%s>" % addr
+    elif m is None:
+        # the sender wants an empty return address
+        return "<>"
     else:
         return "<%s>" % m