diff --git a/Lib/rfc822.py b/Lib/rfc822.py
index 967a85e..8ddac67 100644
--- a/Lib/rfc822.py
+++ b/Lib/rfc822.py
@@ -450,6 +450,7 @@
         expectroute = 0
         self.pos = self.pos + 1
         self.gotonext()
+        adlist = None
         while self.pos < len(self.field):
             if expectroute:
                 self.getdomain()