Title: Why am I getting moderation requests for my unmoderated list?

Question:  My Mailman list is configured so that subscribers can send
messages freely without moderation. Occasionally, however, I receive a
notice saying that a particular message needs my approval before it is
sent to the list. Why do I have to moderate some messages?

Answer:

There are several reasons why Mailman may moderate a particular message
even if your list is configured as an unmoderated list. Luckily, each
moderation notice will give a reason for why the message was moderated so
you don't have to guess. Here are all the reasons, a brief explanation of
each, and the settings involved:

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Reason:  Message body is too big

Explanation: Mailman will compare the size of the incoming message to the
size allowed for each list. By default, any message over 40 KB is held for
moderation. Any message over 3 MB will be returned to sender as
undeliverable.

Setting: To control the maximum message size allowed for your list, go to
General Options and look for the max_message_size setting at the bottom of
the page. You can set it to 0 for the maximum allowable size of 3 MB.

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Reason:  Post to moderated list

Explanation: Individual subscribers can be moderated (rather than having
the entire list moderated for everyone). This is the reason that will be
given if a moderated member sends a message to the list.

Setting: An individual's moderation can be turned on and off on the
Membership List (under Membership Management). The setting that controls
what is done with a message sent by a moderated member is under Privacy
Options -> Sender filters and is called "member_moderation_action."

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Reason:  Post by non-member to a members-only list

Explanation: This reason is given whenever a non-member tries to post to a
list that is configured to only allow members to post.

Setting: The "generic_nonmember_action" setting under Privacy Options ->
Sender filters controls what happens to messages from non-members. It can
be set to either accept messages (no moderation), hold for moderation,
reject, or discard messages.

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Reason:  Message does not have an explicit destination

Explanation: By default, Mailman looks for the list's address in the To or
Cc fields of incoming messages. If the address is not explicitly given in
the To or Cc fields (e.g. if the list has been blind carbon copied or if
the list is subscribed to another list to which the message was originally
sent), the message will be held for approval.

Setting: You can configure the list so that the address is not required to
be in the To or Cc fields by going to Privacy Options -> Recipient filters
and setting the "require_explicit_destination" setting to No.

This is the default setting for all new lists, but it's best to doublecheck.
This MUST be set to NO if you asked to have your old list address
forwarded to the new Mailman list.

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Reason:  Too many recipients to the message

Explanation: Mailman will examine the number of email addresses listed in
the To or Cc fields of incoming messages. By default, Mailman will hold
for moderation any message that contains more than 10 addresses in these
fields (the list's address is only one address and the number of
subscribers on the list does not have an effect on this setting).

Setting: You can change the default setting for "max_num_recipients" under
Privacy Options -> Recipient filters. Change this setting to 0 for no
limit.

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Reason:  Message has a suspicious header

Explanation: Your Mailman list can be configured to moderate messages with
specific headers (e.g. "Subject: On Vacation"). If a message contains such
a header, it will be held for moderation.

Setting: The "bounce_matching_headers" setting under Privacy Options ->
Spam filters contains all headers that Mailman is configured to look for.
You can add or delete headers from this list.

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Update: 02/2004 by Mailman Admin
Date: 06/2003  Author: R. Skiver Thompson