12 files changed, 144 insertions, 88 deletions

diff --git a/src/mailman/chains/docs/moderation.rst b/src/mailman/chains/docs/moderation.rst
index cd0a8eb26..2415b8f4b 100644
--- a/src/mailman/chains/docs/moderation.rst
+++ b/src/mailman/chains/docs/moderation.rst
@@ -33,12 +33,7 @@ determined by the mailing list's settings.  By default, a mailing list is not
 set to moderate new member postings.
 ::
 
-    >>> from mailman.testing.helpers import subscribe
-    >>> member = subscribe(mlist, 'Anne', email='anne@example.com')
-    >>> member
-    <Member: Anne Person <anne@example.com> on test@example.com
-             as MemberRole.member>
-    >>> print(member.moderation_action)
+    >>> print(mlist.default_member_action)
     Action.defer
 
 In order to find out whether the message is held or accepted, we can subscribe
@@ -58,6 +53,18 @@ to Zope events that are triggered on each case.
     ...         for miss in event.msgdata.get('rule_misses', []):
     ...             print('   ', miss)
 
+The user Anne will be a list member. A list member's default moderation action
+is ``None``, meaning that it will use the mailing list's
+``default_member_action``.
+
+    >>> from mailman.testing.helpers import subscribe
+    >>> member = subscribe(mlist, 'Anne', email='anne@example.com')
+    >>> member
+    <Member: Anne Person <anne@example.com> on test@example.com
+             as MemberRole.member>
+    >>> print(member.moderation_action is None)
+    True
+
 Anne's post to the mailing list runs through the incoming runner's default
 built-in chain.  No rules hit and so the message is accepted.
 ::
@@ -173,8 +180,8 @@ Nonmembers
 ==========
 
 Registered nonmembers are handled very similarly to members, the main
-difference being that they usually have a default moderation action.  This is
-how the incoming runner adds sender addresses as nonmembers.
+difference being that the mailing list's default moderation action is
+different. This is how the incoming runner adds sender addresses as nonmembers.
 
     >>> from zope.component import getUtility
     >>> from mailman.interfaces.usermanager import IUserManager
@@ -211,5 +218,11 @@ moderator approval.
     >>> nonmember = mlist.nonmembers.get_member('bart@example.com')
     >>> nonmember
     <Member: bart@example.com on test@example.com as MemberRole.nonmember>
+
+A nonmember's default moderation action is ``None``, meaning that it will use
+the mailing list's ``default_nonmember_action``.
+
     >>> print(nonmember.moderation_action)
+    None
+    >>> print(mlist.default_nonmember_action)
     Action.hold
diff --git a/src/mailman/model/docs/membership.rst b/src/mailman/model/docs/membership.rst
index 0fd748d6a..c8452abf0 100644
--- a/src/mailman/model/docs/membership.rst
+++ b/src/mailman/model/docs/membership.rst
@@ -273,23 +273,26 @@ automatically accepted for posting to the mailing list.
     aperson@example.com MemberRole.owner     Action.accept
     bperson@example.com MemberRole.moderator Action.accept
 
-By default, members have a *deferred* action which specifies that the posting
-should go through the normal moderation checks.
+By default, members and nonmembers have their action set to None, meaning that
+the mailing list's ``default_member_action`` or ``default_nonmember_action``
+will be used.
 
     >>> for member in sorted(mlist.members.members,
     ...                      key=attrgetter('address.email')):
     ...     print(member.address.email, member.role, member.moderation_action)
-    aperson@example.com MemberRole.member Action.defer
-    bperson@example.com MemberRole.member Action.defer
-    cperson@example.com MemberRole.member Action.defer
-    hperson@example.com MemberRole.member Action.defer
-    iperson@example.com MemberRole.member Action.defer
-
-Postings by nonmembers are held for moderator approval by default.
+    aperson@example.com MemberRole.member None
+    bperson@example.com MemberRole.member None
+    cperson@example.com MemberRole.member None
+    hperson@example.com MemberRole.member None
+    iperson@example.com MemberRole.member None
 
     >>> for member in mlist.nonmembers.members:
     ...     print(member.address.email, member.role, member.moderation_action)
-    fperson@example.com MemberRole.nonmember Action.hold
+    fperson@example.com MemberRole.nonmember None
+
+The mailing list's default action for members is *deferred*, which specifies
+that the posting should go through the normal moderation checks. Its default
+action for nonmembers is to hold for moderator approval.
 
 
 Changing subscriptions
diff --git a/src/mailman/model/member.py b/src/mailman/model/member.py
index 99f2de9b8..a6555c0fe 100644
--- a/src/mailman/model/member.py
+++ b/src/mailman/model/member.py
@@ -76,14 +76,10 @@ class Member(Model):
             raise ValueError('subscriber must be a user or address')
         if role in (MemberRole.owner, MemberRole.moderator):
             self.moderation_action = Action.accept
-        elif role is MemberRole.member:
-            self.moderation_action = getUtility(IListManager).get_by_list_id(
-                list_id).default_member_action
         else:
-            assert role is MemberRole.nonmember, (
-                'Invalid MemberRole: {}'.format(role))
-            self.moderation_action = getUtility(IListManager).get_by_list_id(
-                list_id).default_nonmember_action
+            assert role in (MemberRole.member, MemberRole.nonmember), (
+                'Invalid MemberRole: {0}'.format(role))
+            self.moderation_action = None
 
     def __repr__(self):
         return '<Member: {} on {} as {}>'.format(
diff --git a/src/mailman/model/tests/test_member.py b/src/mailman/model/tests/test_member.py
index 3a24d9680..51402b659 100644
--- a/src/mailman/model/tests/test_member.py
+++ b/src/mailman/model/tests/test_member.py
@@ -20,6 +20,7 @@
 import unittest
 
 from mailman.app.lifecycle import create_list
+from mailman.interfaces.action import Action
 from mailman.interfaces.member import MemberRole, MembershipError
 from mailman.interfaces.user import UnverifiedAddressError
 from mailman.interfaces.usermanager import IUserManager
@@ -100,3 +101,23 @@ class TestMember(unittest.TestCase):
         member = self._mlist.members.get_member('anne@example.com')
         member.unsubscribe()
         self.assertEqual(len(list(self._mlist.members.members)), 0)
+
+    def test_default_moderation_action(self):
+        # Owners and moderators have their posts accepted, members and
+        # nonmembers default to the mailing list's action for their type.
+        anne = self._usermanager.create_user('anne@example.com')
+        bart = self._usermanager.create_user('bart@example.com')
+        cris = self._usermanager.create_user('cris@example.com')
+        dana = self._usermanager.create_user('dana@example.com')
+        set_preferred(anne)
+        set_preferred(bart)
+        set_preferred(cris)
+        set_preferred(dana)
+        anne_member = self._mlist.subscribe(anne, MemberRole.owner)
+        bart_member = self._mlist.subscribe(bart, MemberRole.moderator)
+        cris_member = self._mlist.subscribe(cris, MemberRole.member)
+        dana_member = self._mlist.subscribe(dana, MemberRole.nonmember)
+        self.assertEqual(anne_member.moderation_action, Action.accept)
+        self.assertEqual(bart_member.moderation_action, Action.accept)
+        self.assertIsNone(cris_member.moderation_action)
+        self.assertIsNone(dana_member.moderation_action)
diff --git a/src/mailman/rest/docs/addresses.rst b/src/mailman/rest/docs/addresses.rst
index c850503c4..e5dff0f7c 100644
--- a/src/mailman/rest/docs/addresses.rst
+++ b/src/mailman/rest/docs/addresses.rst
@@ -379,7 +379,6 @@ Elle can get her memberships for each of her email addresses.
         http_etag: "..."
         list_id: ant.example.com
         member_id: 1
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/1
         user: http://localhost:9001/3.0/users/4
@@ -390,7 +389,6 @@ Elle can get her memberships for each of her email addresses.
         http_etag: "..."
         list_id: bee.example.com
         member_id: 2
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/2
         user: http://localhost:9001/3.0/users/4
@@ -422,7 +420,6 @@ does not show up in the list of memberships for his other address.
         http_etag: "..."
         list_id: ant.example.com
         member_id: 1
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/1
         user: http://localhost:9001/3.0/users/4
@@ -433,7 +430,6 @@ does not show up in the list of memberships for his other address.
         http_etag: "..."
         list_id: bee.example.com
         member_id: 2
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/2
         user: http://localhost:9001/3.0/users/4
@@ -450,7 +446,6 @@ does not show up in the list of memberships for his other address.
         http_etag: "..."
         list_id: bee.example.com
         member_id: 3
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/3
         user: http://localhost:9001/3.0/users/4
diff --git a/src/mailman/rest/docs/membership.rst b/src/mailman/rest/docs/membership.rst
index 3d2d9a010..ec8765d68 100644
--- a/src/mailman/rest/docs/membership.rst
+++ b/src/mailman/rest/docs/membership.rst
@@ -50,7 +50,6 @@ the REST interface.
         http_etag: ...
         list_id: bee.example.com
         member_id: 1
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/1
         user: http://localhost:9001/3.0/users/1
@@ -67,7 +66,6 @@ Bart's specific membership can be accessed directly:
     http_etag: ...
     list_id: bee.example.com
     member_id: 1
-    moderation_action: defer
     role: member
     self_link: http://localhost:9001/3.0/members/1
     user: http://localhost:9001/3.0/users/1
@@ -88,7 +86,6 @@ the REST interface.
         http_etag: ...
         list_id: bee.example.com
         member_id: 1
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/1
         user: http://localhost:9001/3.0/users/1
@@ -99,7 +96,6 @@ the REST interface.
         http_etag: ...
         list_id: bee.example.com
         member_id: 2
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/2
         user: http://localhost:9001/3.0/users/2
@@ -123,7 +119,6 @@ subscribes, she is returned first.
         http_etag: ...
         list_id: bee.example.com
         member_id: 3
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/3
         user: http://localhost:9001/3.0/users/3
@@ -134,7 +129,6 @@ subscribes, she is returned first.
         http_etag: ...
         list_id: bee.example.com
         member_id: 1
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/1
         user: http://localhost:9001/3.0/users/1
@@ -145,7 +139,6 @@ subscribes, she is returned first.
         http_etag: ...
         list_id: bee.example.com
         member_id: 2
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/2
         user: http://localhost:9001/3.0/users/2
@@ -175,7 +168,6 @@ User ids are different than member ids.
         http_etag: ...
         list_id: ant.example.com
         member_id: 4
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/4
         user: http://localhost:9001/3.0/users/3
@@ -186,7 +178,6 @@ User ids are different than member ids.
         http_etag: ...
         list_id: ant.example.com
         member_id: 5
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/5
         user: http://localhost:9001/3.0/users/2
@@ -197,7 +188,6 @@ User ids are different than member ids.
         http_etag: ...
         list_id: bee.example.com
         member_id: 3
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/3
         user: http://localhost:9001/3.0/users/3
@@ -208,7 +198,6 @@ User ids are different than member ids.
         http_etag: ...
         list_id: bee.example.com
         member_id: 1
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/1
         user: http://localhost:9001/3.0/users/1
@@ -219,7 +208,6 @@ User ids are different than member ids.
         http_etag: ...
         list_id: bee.example.com
         member_id: 2
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/2
         user: http://localhost:9001/3.0/users/2
@@ -238,7 +226,6 @@ We can also get just the members of a single mailing list.
         http_etag: ...
         list_id: ant.example.com
         member_id: 4
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/4
         user: http://localhost:9001/3.0/users/3
@@ -249,7 +236,6 @@ We can also get just the members of a single mailing list.
         http_etag: ...
         list_id: ant.example.com
         member_id: 5
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/5
         user: http://localhost:9001/3.0/users/2
@@ -276,7 +262,6 @@ page.
         http_etag: ...
         list_id: ant.example.com
         member_id: 4
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/4
         user: http://localhost:9001/3.0/users/3
@@ -295,7 +280,6 @@ This works with members of a single list as well as with all members.
         http_etag: ...
         list_id: ant.example.com
         member_id: 4
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/4
         user: http://localhost:9001/3.0/users/3
@@ -353,7 +337,6 @@ mailing list.
         http_etag: ...
         list_id: ant.example.com
         member_id: 4
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/4
         user: http://localhost:9001/3.0/users/3
@@ -364,7 +347,6 @@ mailing list.
         http_etag: ...
         list_id: ant.example.com
         member_id: 5
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/5
         user: http://localhost:9001/3.0/users/2
@@ -386,7 +368,6 @@ mailing list.
         http_etag: ...
         list_id: bee.example.com
         member_id: 3
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/3
         user: http://localhost:9001/3.0/users/3
@@ -397,7 +378,6 @@ mailing list.
         http_etag: ...
         list_id: bee.example.com
         member_id: 1
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/1
         user: http://localhost:9001/3.0/users/1
@@ -408,7 +388,6 @@ mailing list.
         http_etag: ...
         list_id: bee.example.com
         member_id: 2
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/2
         user: http://localhost:9001/3.0/users/2
@@ -467,7 +446,6 @@ example, we can search for all the memberships of a particular address.
         http_etag: ...
         list_id: ant.example.com
         member_id: 4
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/4
         user: http://localhost:9001/3.0/users/3
@@ -478,7 +456,6 @@ example, we can search for all the memberships of a particular address.
         http_etag: ...
         list_id: bee.example.com
         member_id: 3
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/3
         user: http://localhost:9001/3.0/users/3
@@ -498,7 +475,6 @@ Or, we can find all the memberships for a particular mailing list.
         http_etag: ...
         list_id: bee.example.com
         member_id: 3
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/3
         user: http://localhost:9001/3.0/users/3
@@ -509,7 +485,6 @@ Or, we can find all the memberships for a particular mailing list.
         http_etag: ...
         list_id: bee.example.com
         member_id: 1
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/1
         user: http://localhost:9001/3.0/users/1
@@ -520,7 +495,6 @@ Or, we can find all the memberships for a particular mailing list.
         http_etag: ...
         list_id: bee.example.com
         member_id: 2
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/2
         user: http://localhost:9001/3.0/users/2
@@ -553,7 +527,6 @@ list.
         http_etag: ...
         list_id: bee.example.com
         member_id: 2
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/2
         user: http://localhost:9001/3.0/users/2
@@ -585,7 +558,6 @@ Or, we can find all the memberships for an address with a specific role.
         http_etag: ...
         list_id: ant.example.com
         member_id: 5
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/5
         user: http://localhost:9001/3.0/users/2
@@ -596,7 +568,6 @@ Or, we can find all the memberships for an address with a specific role.
         http_etag: ...
         list_id: bee.example.com
         member_id: 2
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/2
         user: http://localhost:9001/3.0/users/2
@@ -618,7 +589,6 @@ Finally, we can search for a specific member given all three criteria.
         http_etag: ...
         list_id: bee.example.com
         member_id: 2
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/2
         user: http://localhost:9001/3.0/users/2
@@ -640,7 +610,6 @@ Search can also be performed using HTTP GET queries.
         http_etag: ...
         list_id: bee.example.com
         member_id: 2
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/2
         user: http://localhost:9001/3.0/users/2
@@ -699,7 +668,6 @@ Elly is now a known user, and a member of the mailing list.
         http_etag: ...
         list_id: ant.example.com
         member_id: 8
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/8
         user: http://localhost:9001/3.0/users/5
@@ -746,7 +714,6 @@ list with her preferred address.
         http_etag: "..."
         list_id: ant.example.com
         member_id: 9
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/9
         user: http://localhost:9001/3.0/users/6
@@ -772,7 +739,6 @@ the new address.
         http_etag: "..."
         list_id: ant.example.com
         member_id: 9
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/9
         user: http://localhost:9001/3.0/users/6
@@ -840,7 +806,6 @@ addresses.
         http_etag: "..."
         list_id: ant.example.com
         member_id: 10
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/10
         user: http://localhost:9001/3.0/users/7
@@ -852,7 +817,6 @@ addresses.
         http_etag: "..."
         list_id: bee.example.com
         member_id: 11
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/11
         user: http://localhost:9001/3.0/users/7
@@ -911,7 +875,6 @@ his membership ids have not changed.
         http_etag: "..."
         list_id: ant.example.com
         member_id: 10
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/10
         user: http://localhost:9001/3.0/users/7
@@ -922,7 +885,6 @@ his membership ids have not changed.
         http_etag: "..."
         list_id: bee.example.com
         member_id: 11
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/11
         user: http://localhost:9001/3.0/users/7
@@ -952,7 +914,6 @@ mode of delivery.
         http_etag: "..."
         list_id: bee.example.com
         member_id: 11
-        moderation_action: defer
         role: member
         self_link: http://localhost:9001/3.0/members/11
         user: http://localhost:9001/3.0/users/7
@@ -970,9 +931,14 @@ The moderation action for a member can be changed by PATCH'ing the
 
     >>> dump_json('http://localhost:9001/3.0/members/10')
     address: http://localhost:9001/3.0/addresses/hperson@example.com
-    ...
-    moderation_action: defer
-    ...
+    delivery_mode: regular
+    email: hperson@example.com
+    http_etag: "6d544208d60e578189fc023748f1ec467290abb5"
+    list_id: ant.example.com
+    member_id: 10
+    role: member
+    self_link: http://localhost:9001/3.0/members/10
+    user: http://localhost:9001/3.0/users/7
 
     >>> dump_json('http://localhost:9001/3.0/members/10', {
     ...           'moderation_action': 'hold',
diff --git a/src/mailman/rest/members.py b/src/mailman/rest/members.py
index b56fa3c8d..c842ccd7d 100644
--- a/src/mailman/rest/members.py
+++ b/src/mailman/rest/members.py
@@ -61,10 +61,12 @@ class _MemberBase(CollectionMixin):
             email=member.address.email,
             list_id=member.list_id,
             member_id=member_id,
-            moderation_action=member.moderation_action,
             role=role,
             self_link=self.api.path_to('members/{}'.format(member_id)),
             )
+        # Add the moderation action if there is one.
+        if member.moderation_action is not None:
+            response['moderation_action'] = member.moderation_action
         # Add the user link if there is one.
         user = member.user
         if user is not None:
diff --git a/src/mailman/rules/docs/moderation.rst b/src/mailman/rules/docs/moderation.rst
index f5ceec29a..56602189b 100644
--- a/src/mailman/rules/docs/moderation.rst
+++ b/src/mailman/rules/docs/moderation.rst
@@ -2,9 +2,10 @@
 Moderation
 ==========
 
-All members and nonmembers have a moderation action.  When the action is not
-`defer`, the `moderation` rule flags the message as needing moderation.  This
-might be to automatically accept, discard, reject, or hold the message.
+All members and nonmembers have a moderation action, which defaults to the
+list's default action.  When the action is not `defer`, the `moderation` rule
+flags the message as needing moderation.  This might be to automatically
+accept, discard, reject, or hold the message.
 
 Two separate rules check for member and nonmember moderation.  Member
 moderation happens early in the built-in chain, while nonmember moderation
@@ -30,7 +31,7 @@ postings are not moderated.
              as MemberRole.member>
 
     >>> member = mlist.members.get_member('aperson@example.com')
-    >>> print(member.moderation_action)
+    >>> print(mlist.default_member_action)
     Action.defer
 
 Because Anne is not moderated, the member moderation rule does not match.
@@ -44,9 +45,9 @@ Because Anne is not moderated, the member moderation rule does not match.
     >>> member_rule.check(mlist, member_msg, {})
     False
 
-Once the member's moderation action is set to something other than `defer`,
-the rule matches.  Also, the message metadata has a few extra pieces of
-information for the eventual moderation chain.
+Once the member's moderation action is set to something other than `defer` or
+``None``, the rule matches.  Also, the message metadata has a few extra pieces
+of information for the eventual moderation chain.
 
     >>> from mailman.interfaces.action import Action
     >>> member.moderation_action = Action.hold
@@ -78,7 +79,7 @@ Bart, who is not a member of the mailing list, sends a message to the list.
              as MemberRole.nonmember>
 
     >>> nonmember = mlist.nonmembers.get_member('bperson@example.com')
-    >>> print(nonmember.moderation_action)
+    >>> print(mlist.default_nonmember_action)
     Action.hold
 
 When Bart is registered as a nonmember of the list, his moderation action is
diff --git a/src/mailman/rules/moderation.py b/src/mailman/rules/moderation.py
index fdecd1d5f..9c89cf0b2 100644
--- a/src/mailman/rules/moderation.py
+++ b/src/mailman/rules/moderation.py
@@ -42,8 +42,10 @@ class MemberModeration:
         """See `IRule`."""
         for sender in msg.senders:
             member = mlist.members.get_member(sender)
-            action = (None if member is None
-                      else member.moderation_action)
+            if member is None:
+                return False
+            action = (member.moderation_action
+                      or mlist.default_member_action)
             if action is Action.defer:
                 # The regular moderation rules apply.
                 return False
@@ -112,7 +114,8 @@ class NonmemberModeration:
                         _record_action(msgdata, action, sender,
                                        reason.format(action))
                         return True
-            action = nonmember.moderation_action
+            action = (nonmember.moderation_action
+                      or mlist.default_nonmember_action)
             if action is Action.defer:
                 # The regular moderation rules apply.
                 return False
diff --git a/src/mailman/rules/tests/test_moderation.py b/src/mailman/rules/tests/test_moderation.py
index df1658792..3e80aeeb5 100644
--- a/src/mailman/rules/tests/test_moderation.py
+++ b/src/mailman/rules/tests/test_moderation.py
@@ -144,3 +144,60 @@ A message body.
             self.assertEqual(
                 msgdata['moderation_action'], action_name,
                 'Wrong action for {}: {}'.format(address, action_name))
+
+    def test_nonmember_fallback_to_list_defaults(self):
+        # https://gitlab.com/mailman/mailman/issues/189
+        self._mlist.default_nonmember_action = Action.hold
+        user_manager = getUtility(IUserManager)
+        user_manager.create_address('anne@example.com')
+        rule = moderation.NonmemberModeration()
+        msg = mfs("""\
+From: anne@example.com
+To: test@example.com
+Subject: A test message
+Message-ID: <ant>
+MIME-Version: 1.0
+
+A message body.
+""")
+        # First, the message should get held
+        msgdata = {}
+        result = rule.check(self._mlist, msg, msgdata)
+        self.assertTrue(result)
+        self.assertEqual(msgdata.get('moderation_action'), 'hold')
+        # Then the list's default nonmember action is changed
+        self._mlist.default_nonmember_action = Action.discard
+        msg.replace_header('Message-ID', '<ant2>')
+        # This time, the message should be discarded
+        result = rule.check(self._mlist, msg, msgdata)
+        self.assertTrue(result)
+        self.assertEqual(msgdata.get('moderation_action'), 'discard')
+
+    def test_member_fallback_to_list_defaults(self):
+        # https://gitlab.com/mailman/mailman/issues/189
+        self._mlist.default_member_action = Action.accept
+        user_manager = getUtility(IUserManager)
+        anne = user_manager.create_address('anne@example.com')
+        self._mlist.subscribe(anne, MemberRole.member)
+        rule = moderation.MemberModeration()
+        msg = mfs("""\
+From: anne@example.com
+To: test@example.com
+Subject: A test message
+Message-ID: <ant>
+MIME-Version: 1.0
+
+A message body.
+""")
+        # First, the message should get held
+        msgdata = {}
+        result = rule.check(self._mlist, msg, msgdata)
+        self.assertTrue(result)
+        self.assertEqual(msgdata.get('moderation_action'), 'accept')
+        # Then the list's default nonmember action is changed
+        self._mlist.default_member_action = Action.hold
+        msg.replace_header('Message-ID', '<ant2>')
+        # This time, the message should be discarded
+        result = rule.check(self._mlist, msg, msgdata)
+        self.assertTrue(result)
+        self.assertEqual(msgdata.get('moderation_action'), 'hold')
diff --git a/src/mailman/utilities/importer.py b/src/mailman/utilities/importer.py
index 9a5684d9c..da19613d8 100644
--- a/src/mailman/utilities/importer.py
+++ b/src/mailman/utilities/importer.py
@@ -576,8 +576,6 @@ def import_roster(mlist, config_dict, members, role, action=None):
                 # option to know which action should be taken.
                 action = member_moderation_action_mapping(
                     config_dict.get("member_moderation_action"))
-            else:
-                action = Action.accept
         if action is not None:
             # Either this was set right above or in the function's arguments
             # for nonmembers.
diff --git a/src/mailman/utilities/tests/test_import.py b/src/mailman/utilities/tests/test_import.py
index 637f78585..83161bf1f 100644
--- a/src/mailman/utilities/tests/test_import.py
+++ b/src/mailman/utilities/tests/test_import.py
@@ -1112,9 +1112,10 @@ class TestPreferencesImport(unittest.TestCase):
         self._do_test(128, dict(moderation_action=Action.discard))
 
     def test_no_moderate(self):
-        # If option flag Moderate is not set, action is accept
+        # If option flag Moderate is not set, action is None (fallback to the
+        # mailing list's action).
         self._pckdict['member_moderation_action'] = 1          # reject
-        self._do_test(0, dict(moderation_action=Action.accept))
+        self._do_test(0, dict(moderation_action=None))
 
     def test_multiple_options(self):
         # DontReceiveDuplicates & DisableMime & SuppressPasswordReminder