Moderation¶
Posts by members and nonmembers are subject to moderation checks during incoming processing. Different situations can cause such posts to be held for moderator approval.
>>> from mailman.app.lifecycle import create_list
>>> mlist = create_list('test@example.com')
Members and nonmembers have a moderation action which can shortcut the normal moderation checks. The built-in chain does just a few checks first, such as seeing if the message has a matching Approved: header, or if the emergency flag has been set on the mailing list, or whether a mail loop has been detected.
Mailing lists have a default moderation action, one for members and another
for nonmembers. If a member’s moderation action is None
, then the member
moderation check falls back to the appropriate list default.
A moderation action of defer means that no explicit moderation check is performed and the rest of the rule chain processing proceeds as normal. But it is also common for first-time posters to have a hold action, meaning that their messages are held for moderator approval for a while.
Nonmembers almost always have a hold action, though some mailing lists may choose to set this default action to discard, meaning their posts would be immediately thrown away.
Member moderation¶
Posts by list members are moderated if the member’s moderation action is not deferred. The default setting for the moderation action of new members is determined by the mailing list’s settings. By default, a mailing list is not set to moderate new member postings.
>>> print(mlist.default_member_action)
Action.defer
In order to find out whether the message is held or accepted, we can subscribe to internal events that are triggered on each case.
>>> from mailman.interfaces.chain import ChainEvent
>>> def on_chain(event):
... if isinstance(event, ChainEvent):
... print(event)
... print(event.chain)
... print('Subject:', event.msg['subject'])
... print('Hits:')
... for hit in event.msgdata.get('rule_hits', []):
... print(' ', hit)
... print('Misses:')
... for miss in event.msgdata.get('rule_misses', []):
... print(' ', miss)
Anne is a list member with moderation action of None
so that moderation
will fall back to 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)
None
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.
>>> from mailman.testing.helpers import (specialized_message_from_string
... as message_from_string)
>>> msg = message_from_string("""\
... From: anne@example.com
... To: test@example.com
... Subject: aardvark
...
... This is a test.
... """)
>>> from mailman.core.chains import process
>>> from mailman.testing.helpers import event_subscribers
>>> with event_subscribers(on_chain):
... process(mlist, msg, {}, 'default-posting-chain')
<mailman.interfaces.chain.AcceptEvent ...>
<mailman.chains.accept.AcceptChain ...>
Subject: aardvark
Hits:
Misses:
dmarc-mitigation
no-senders
approved
emergency
loop
banned-address
member-moderation
nonmember-moderation
administrivia
implicit-dest
max-recipients
max-size
news-moderation
no-subject
digests
suspicious-header
However, when Anne’s moderation action is set to hold, her post is held for moderator approval.
>>> from mailman.interfaces.action import Action
>>> member.moderation_action = Action.hold
>>> msg = message_from_string("""\
... From: anne@example.com
... To: test@example.com
... Subject: badger
...
... This is a test.
... """)
>>> with event_subscribers(on_chain):
... process(mlist, msg, {}, 'default-posting-chain')
<mailman.interfaces.chain.HoldEvent ...>
<mailman.chains.hold.HoldChain ...>
Subject: badger
Hits:
member-moderation
Misses:
dmarc-mitigation
no-senders
approved
emergency
loop
banned-address
Anne’s moderation action can also be set to discard…
>>> member.moderation_action = Action.discard
>>> msg = message_from_string("""\
... From: anne@example.com
... To: test@example.com
... Subject: cougar
...
... This is a test.
... """)
>>> with event_subscribers(on_chain):
... process(mlist, msg, {}, 'default-posting-chain')
<mailman.interfaces.chain.DiscardEvent ...>
<mailman.chains.discard.DiscardChain ...>
Subject: cougar
Hits:
member-moderation
Misses:
dmarc-mitigation
no-senders
approved
emergency
loop
banned-address
… or reject.
>>> member.moderation_action = Action.reject
>>> msg = message_from_string("""\
... From: anne@example.com
... To: test@example.com
... Subject: dingo
...
... This is a test.
... """)
>>> with event_subscribers(on_chain):
... process(mlist, msg, {}, 'default-posting-chain')
<mailman.interfaces.chain.RejectEvent ...>
<mailman.chains.reject.RejectChain ...>
Subject: dingo
Hits:
member-moderation
Misses:
dmarc-mitigation
no-senders
approved
emergency
loop
banned-address
Nonmembers¶
Registered nonmembers are handled very similarly to members, except that a different list default setting is used when moderating nonmemberds. This is how the incoming runner adds sender addresses as nonmembers.
>>> from zope.component import getUtility
>>> from mailman.interfaces.usermanager import IUserManager
>>> user_manager = getUtility(IUserManager)
>>> address = user_manager.create_address('bart@example.com')
>>> address
<Address: bart@example.com [not verified] at ...>
When the moderation rule runs on a message from this sender, this address will be registered as a nonmember of the mailing list, and it will be held for moderator approval.
>>> msg = message_from_string("""\
... From: bart@example.com
... To: test@example.com
... Subject: elephant
...
... """)
>>> with event_subscribers(on_chain):
... process(mlist, msg, {}, 'default-posting-chain')
<mailman.interfaces.chain.HoldEvent ...>
<mailman.chains.hold.HoldChain ...>
Subject: elephant
Hits:
nonmember-moderation
Misses:
dmarc-mitigation
no-senders
approved
emergency
loop
banned-address
member-moderation
>>> nonmember = mlist.nonmembers.get_member('bart@example.com')
>>> nonmember
<Member: bart@example.com on test@example.com as MemberRole.nonmember>
When a nonmember’s default moderation action is None
, the rule will use
the mailing list’s default_nonmember_action
.
>>> print(nonmember.moderation_action)
None
>>> print(mlist.default_nonmember_action)
Action.hold