Rules

Rules are applied to each message as part of a rule chain. Individual rules simply return a boolean specifying whether the rule matches or not. Chain links determine what happens when a rule matches.

All rules

Rules are maintained in the configuration object as a dictionary mapping rule names to rule objects.

>>> from zope.interface.verify import verifyObject
>>> from mailman.interfaces.rules import IRule
>>> from mailman.config import config
>>> for rule_name in sorted(config.rules):
...     rule = config.rules[rule_name]
...     print(rule_name, verifyObject(IRule, rule))
administrivia True
any True
approved True
banned-address True
digests True
dmarc-mitigation True
emergency True
implicit-dest True
loop True
max-recipients True
max-size True
member-moderation True
news-moderation True
no-senders True
no-subject True
nonmember-moderation True
suspicious-header True
truth True

You can get a rule by name.

>>> rule = config.rules['emergency']
>>> verifyObject(IRule, rule)
True

Rule checks

Individual rules can be checked to see if they match, by running the rule’s check() method. This returns a boolean indicating whether the rule was matched or not.

>>> from mailman.app.lifecycle import create_list
>>> mlist = create_list('_xtest@example.com')
>>> from mailman.testing.helpers import (specialized_message_from_string
...   as message_from_string)
>>> msg = message_from_string("""\
... From: aperson@example.com
...
... An important message.
... """)

For example, the emergency rule just checks to see if the emergency flag is set on the mailing list, and the message has not been pre-approved by the list administrator.

>>> print(rule.name)
emergency
>>> mlist.emergency = False
>>> rule.check(mlist, msg, {})
False
>>> mlist.emergency = True
>>> rule.check(mlist, msg, {})
True
>>> rule.check(mlist, msg, dict(moderator_approved=True))
False