Merge the Python 3 branch.

1 files changed, 6 insertions, 9 deletions

diff --git a/src/mailman/app/bounces.py b/src/mailman/app/bounces.py
index b0a316ad6..ebfe63cff 100644
--- a/src/mailman/app/bounces.py
+++ b/src/mailman/app/bounces.py
@@ -17,9 +17,6 @@
 
 """Application level bounce handling."""
 
-from __future__ import absolute_import, print_function, unicode_literals
-
-__metaclass__ = type
 __all__ = [
     'ProbeVERP',
     'StandardVERP',
@@ -36,10 +33,6 @@ import logging
 from email.mime.message import MIMEMessage
 from email.mime.text import MIMEText
 from email.utils import parseaddr
-from string import Template
-from zope.component import getUtility
-from zope.interface import implementer
-
 from mailman.config import config
 from mailman.core.i18n import _
 from mailman.email.message import OwnerNotification, UserNotification
@@ -50,6 +43,10 @@ from mailman.interfaces.subscriptions import ISubscriptionService
 from mailman.utilities.email import split_email
 from mailman.utilities.i18n import make
 from mailman.utilities.string import oneline
+from string import Template
+from zope.component import getUtility
+from zope.interface import implementer
+
 
 log = logging.getLogger('mailman.config')
 elog = logging.getLogger('mailman.error')
@@ -71,8 +68,8 @@ def bounce_message(mlist, msg, error=None):
     :type error: Exception
     """
     # Bounce a message back to the sender, with an error message if provided
-    # in the exception argument.
-    if msg.sender is None:
+    # in the exception argument.  .sender might be None or the empty string.
+    if not msg.sender:
         # We can't bounce the message if we don't know who it's supposed to go
         # to.
         return