2 files changed, 39 insertions, 1 deletions

diff --git a/src/mailman/app/docs/message.rst b/src/mailman/app/docs/message.rst
index 3e3293196..11ab32b22 100644
--- a/src/mailman/app/docs/message.rst
+++ b/src/mailman/app/docs/message.rst
@@ -46,3 +46,41 @@ The message will end up in the `virgin` queue.
     Precedence: bulk
     <BLANKLINE>
     I needed to tell you this.
+
+The message above got a Precedence: bulk header added by default.  If the
+message we're sending already has a Precedence: header, it shouldn't be
+changed.
+
+    >>> del msg['precedence']
+    >>> msg['Precedence'] = 'list'
+    >>> msg.send(mlist)
+
+Again, the message will end up in the `virgin` queue but with our Precedence:
+header.
+
+    >>> switchboard = config.switchboards['virgin']
+    >>> len(switchboard.files)
+    1
+    >>> filebase = switchboard.files[0]
+    >>> qmsg, qmsgdata = switchboard.dequeue(filebase)
+    >>> switchboard.finish(filebase)
+    >>> qmsg['precedence'] == 'list'
+    True
+
+Sometimes we want to send the message without a Precedence: header such as
+when we send a probe message.
+
+    >>> del msg['precedence']
+    >>> msg.send(mlist, noprecedence=True)
+
+Again, the message will end up in the `virgin` queue but without the
+Precedence: header.
+
+    >>> switchboard = config.switchboards['virgin']
+    >>> len(switchboard.files)
+    1
+    >>> filebase = switchboard.files[0]
+    >>> qmsg, qmsgdata = switchboard.dequeue(filebase)
+    >>> switchboard.finish(filebase)
+    >>> 'precedence' in qmsg
+    False
diff --git a/src/mailman/email/message.py b/src/mailman/email/message.py
index 7f7ee66ed..28d94523f 100644
--- a/src/mailman/email/message.py
+++ b/src/mailman/email/message.py
@@ -193,7 +193,7 @@ class UserNotification(Message):
         # UserNotifications are typically for admin messages, and for messages
         # other than list explosions.  Send these out as Precedence: bulk, but
         # don't override an existing Precedence: header.
-        if 'precedence' not in self or not noprecedence:
+        if 'precedence' not in self and not noprecedence:
             self['Precedence'] = 'bulk'
         self._enqueue(mlist, **_kws)