Interpret Mailing List Moderation Messages


Learn about list moderation messages and how to adjust moderation settings.


Critical Concepts

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.


Steps to Take

Messages from the list owner are moderated

Mailman does not automatically recognize messages from the list owner and distribute them without moderation. Instead, Mailman looks to see whether you are subscribed to your list and what the moderation rule is for you as a subscriber or non-subscriber.

Most often, owners whose messages are being moderated are not subscribed to their own list.

You can either add yourself as a subscriber to the list or accept yourself as a non-member:

  1. Log in to the list's administration page: with your Active Directory username and password (replace ListName with the actual name of your list. The final character is a lowercase letter 'L' for 'list.')
  2. Find Configuration Categories at the top of the page. Then select Privacy Options > Sender filters.
  3. Add your email address to accept_these_nonmembers.
  4. Submit your changes.

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 10 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 10 MB.

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.

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.

Message has implicit 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.

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.

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.

Posting to a moderated newsgroup

Explanation: Your Mailman list can be configured to also send copies of messages to an existing newsgroup. You can specify whether or not that newsgroup is moderated in the MailNews Gateways section of the admin pages.

Setting: If the news_moderation setting under MailNews Gateways is set to Moderated, messages sent to your Mailman list will be held for moderation. Note that even if the list is not configured to be linked to a newsgroup, the news_moderation setting will still affect list moderation.  

If you still have questions or need additional assistance, please submit a ticket or call the ITS Service Desk at (858) 246-4357