1 files changed, 7 insertions, 0 deletions

diff --git a/src/mailman/core/pipelines.py b/src/mailman/core/pipelines.py
index 15adca501..7efc8e329 100644
--- a/src/mailman/core/pipelines.py
+++ b/src/mailman/core/pipelines.py
@@ -26,6 +26,8 @@ __all__ = [
     ]
 
 
+import logging
+
 from zope.interface import implements
 from zope.interface.verify import verifyObject
 
@@ -35,6 +37,8 @@ from mailman.core.i18n import _
 from mailman.interfaces.handler import IHandler
 from mailman.interfaces.pipeline import IPipeline
 
+log = logging.getLogger('mailman.debug')
+
 
 
 def process(mlist, msg, msgdata, pipeline_name='built-in'):
@@ -45,8 +49,11 @@ def process(mlist, msg, msgdata, pipeline_name='built-in'):
     :param msgdata: The message metadata dictionary.
     :param pipeline_name: The name of the pipeline to process through.
     """
+    message_id = msg.get('message-id', 'n/a')
     pipeline = config.pipelines[pipeline_name]
     for handler in pipeline:
+        log.debug('[pipeline] processing {0}: {1}'.format(
+            handler.name, message_id))
         handler.process(mlist, msg, msgdata)