[Mailman-Users] Replying to digests

Mark Sapiro mark at msapiro.net
Tue Dec 29 16:05:40 CET 2009

Clare Redstone wrote:
>I'm in the process of setting up Mailman for a discussion group of about 100
>members. From past experience, I know some people will prefer to have digest
>but they'll also probably just hit the "reply" button without editing the
>subject or deleting anything automatically included. I think this will mean
>their replies will contain the entire digest: difficult to work out which
>message they're replying to and using archive space on the server.
>1.       How do I stop this happening?
>At the moment, the only thing I can think of is to filter out messages
>containing "digest" in the subject line and hold those for moderation.

You can do that with Privacy options ... -> Spam filters ->
header_filter_rules, or you can just moderate all members or all
digest members and reject their posts until they learn. You can also
set General Options -> max_message_size small enough to catch these.
In particular, if digests are triggered on size only, you should be
able to find a sweet spot that will catch all quoted digests but not
most 'good' posts.	

>2.       Can I also filter messages with "digest" in the body? I can't see
>where to do this in the administrative interface.

No. Filtering on anything in the message body requires a custom
handler. See the FAQ at <http://wiki.list.org/x/l4A9>.

>3.       When I'm reviewing a message held for moderation, can I edit it to
>remove unwanted bits of the digest? I need to do this without altering the
>sender's details so members know the message is from them and not from me?
>When I click on the message in the moderation queue, I can see a message
>excerpt but can't see how to edit it.

Without source modifications, you can't edit a held message from the
admindb interface. What you can do depends on your MUA. I do the
following occasionally (when a quoted digest is held for size). I have
admin_immed_notify set to yes, so I receive a notice containing the
post as part 2 of 3 message parts. First, I discard the original held
message. Then, using Mutt, I open the notice and then the
message/rfc822 part containing the post, edit it and then 'bounce' it
to the list. 'Bounce' is Mutt's term for resending the original
message to additional recipients. This is not forwarding; it is
resending with the original headers. Not all MUAs can do this.

Also see the FAQ at <http://wiki.list.org/x/24A9>.

OTOH, you'll get more mileage in the long run by rejecting the post and
requiring the user to generate a proper reply.

>4.       If messages have got through with lots of unwanted text, is it
>possible for me to edit them in the archive? Otherwise my archive may be
>unnecessarily large and I can't afford endless server space.

This requires shell access to the server. See the FAQ at
<http://wiki.list.org/x/OAB0>. (Note: These days, file space is a lot
cheaper than your time to do this, even if you do it as a hobby.)

Also note that if the members subscribe to the MIME format digest (make
it the default), many MUAs allow opening an individual message from
the digest and replying to it alone. It might be easier to train your
users if they have this ability.

Aside: I would think this behavior would be self correcting as it
renders digests (particularly plain format digests) virtually
unreadable, but the ability of users to blindly act in opposition to
their own interests continues to amaze me. I guess that when replying
to the current digest, the readability of the next digest is what
economists call an externality.

Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

More information about the Mailman-Users mailing list