[Mailman-Users] Allow discard-and-forward for spam filters?

Adrian Pepper arpepper at uwaterloo.ca
Wed Mar 30 08:49:15 EDT 2016


Because of centralized administration of mailman server used by many
campus units, and other general inertia, we still use 2.1.12 (a couple
of local mods; I know of one for sure for recognizing alternative email

So I am wondering if later versions of Mailman 2 have added something
which seems to me to be obviously missing.

In (showing a representative, not necessarily real, URL)
you can choose to "discard" most messages and check "forward
discarded messages to the moderator".

However, in
you can only Dicard or Hold.
(Complete list Defer, Hold, Reject, Discard, Accept).

It would be nice if for each filter rule individually you
could choose "discard and forward to moderator".

Has that actually been implemented in subsequent versions of Mailman 2,
i.e. between 2.1.12 and 2.1.21 ?

I assume in Version 3 the filter capabilities have been completely
redone and probably regularized.

It began to seem prudent for us to hold "slightly spammy" mail for
inspection.  A problem is that the majority of those would have been
rejected by the sender filters anyway (though we're interested in
those that wouldn't), so this has resulted in a lot of extra moderator

Now certainly we wouldn't want [or would appreciate the choice
not] to "forward to moderator" all discards on the /spam page.
And, really, the "does this fail the membership (filter) requirements"
is something you'd like to be able to determine in the spam filters.
(And simply discard those, perhaps forwarding if they are not too
spammy).  (Because really really we'd like to "hold" slightly spammy
messages which meet membership requirements, but discard-and-forward
the others, but discarding-and-forwarding-to-moderator all would be
reasonable compromise).

I wondered too about combined expressions (and negation).
Those don't look easy to do.

     header_filter_rules (privacy): Filter rules to match against the
     headers of a message.

     Each header filter rule has two parts, a list of regular
     expressions, one per line, and an action to take. Mailman matches
     the message's headers against every regular expression in the rule
     and if any match, the message is rejected, held, or discarded
     based on the action you specify. Use Defer to temporarily disable
     a rule. You can have more than one filter rule for your list. In
     that case, each rule is matched in turn, with processing stopped
     after the first match. Note that headers are collected from all
     the attachments (except for the mailman administrivia message) and
     matched against the regular expressions.  With this feature, you
     can effectively sort out messages with dangerous file types or
     file name extensions.

Since you can always add multiple rules to achieve "or", it seems
unfortunate (but past history now) that multiple expressions don't "and".

Anyway, my simple question is "did Mailman 2 sometime after 2.1.12 gain
the ability to 'dicard and forward to moderator'" as an option for each
spam filter rule?

(Along with the implicit suggestion that that would be a useful option).
(And the longer-term suggestion for AND and negation).

Adrian Pepper

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