Clean up a bare except: clause.
diff --git a/Lib/rfc822.py b/Lib/rfc822.py
index 14fd2a8..3a02224 100644
--- a/Lib/rfc822.py
+++ b/Lib/rfc822.py
@@ -74,7 +74,7 @@
             # (and then assume seek() works, too)
             try:
                 fp.tell()
-            except:
+            except (AttributeError, IOError):
                 seekable = 0
             else:
                 seekable = 1