Mailing Lists – FAQ
Roles in Mailman:
|Subscriber||A subscriber is someone who has subscribed to a list, receives messages posted to the list, and may also post messages for distribution to the list if permitted. Who may post, and how it is done, may be controlled by the list owners. A subscriber has no administrative power over list operation but can change a few of his or her own subscription settings. For example, a subscriber can decide to receive message "digests" rather than individual postings.|
|Owner||Each list must have an owner who is responsible for configuration, maintenance and operation of the list. The list owner may establish other owners, and may optionally have others take roles such as moderating the discussion or managing subscription requests. List owners may execute commands for their subscribers including adding and deleting subscribers.|
|Moderator||List moderators are optional. They are assigned by the owners and can manage list subscriptions and postings.|
Common Bounce Messages:
Why am I constantly receiving "Discarded" email notifications?
The default setting in Mailman is to discard any emails from addresses that are not subscribers. This is done to avoid spam getting through, however you can choose to adjust it if it suits your list.
The option is available under “Privacy Options” > “Sender Filters”
Towards the bottom under: Action to take for postings from non-members for which no explicit action is defined.
Instead of “Discard”, which is currently selected, you may choose “Accept” or “Hold”, if you would prefer to okay certain messages.
If you have subscribers trying to send from another email address, you may want to add the alternate email address as a subscriber as well, or recommend they send messages from the subscribed address.
Why am I getting moderation requests for my unmoderated list?
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:
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 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.
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 %gt; Sender filters and is called “member_moderation_action.”
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.
Reason: 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.
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.
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.
Reason: 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. Please note that even if the list is not configured to be linked to a newsgroup, the “news_moderation” setting will still affect list moderation.
How can I send emails to list subscribers?
All lists on the Mailman server at Colorado State University have email addresses of the form <listname>@lists.colostate.edu. For example, to post to a list called csusports, you send email to firstname.lastname@example.org.
Messages sent to these addresses first go to the Mailman server. Mailman receives the message and processes it, checking for errors and following the rules established by the list owners. If a message is valid, a copy is forwarded to each of the list’s subscribers.
Forgot your password?
Each list has its own individual password for administrative access. If you do not remember your password, you can use the password tools at your list’s page:
where listname is replaced by the name of your list.
How can I be added as an owner to an existing list?
Only the current owner of the list may give this permission. To see the owner of a list go to its information page:
where listname is replaced with the specific list name. The owner(s) will be listed at the bottom of the page.
How do I add/remove additional owners?
As a Mailman list owner, you can add or delete owners at any time. Under “General Options” you will find an owner setting where you can specify the email address(es) of the current list owner(s). Simply add or delete email addresses to add or remove list owners. When you are finished, click on the “Submit Your Changes” button. It is a good idea to then double-check the spelling of the owner addresses.
How do I add/remove subscribers?
You can add and remove subscribers by going to your list’s administration pages at:
(where listname is replaced by the name of your list).
After you have entered the list administrator password, go to “Membership Management.” This should bring you to a page with a list of the subscribers. Every subscriber will have a checkbox at the left, entitled “unsub.” If you wish to unsubscribe a few people, you can check the boxes and click on “Submit Your Changes.”
If you have a list of email addresses that you wish to add or remove, you can go to either “Mass Subscription” or “Mass Removal,” which are options under “Membership Management.”
For “Mass Subscription” enter the email addresses in the text box provided, one per line. If you would like to include a name associated with each address, you can do so in the following format:
Don’t forget to include the brackets around the email address. It is also very important that you include the full email address.
Alternatively, you can provide a CSV or plain text file containing the email addresses (and names if preferred). Type the location of the file in the “…or specify a file to upload” box or use the “Browse…” button to locate it on your computer.
For the “Mass Removal” page, just enter the email addresses you want to remove, one per line, or provide a text file. The file should contain email addresses only, one per line, with no names.
Can I upload a CSV file for adding subscribers?
You can upload a txt or csv file as long as it contains only the email addresses, one per line. Something to note, if using an excel spreadsheet to keep track of your addresses, you cannot upload it directly, but you can copy & paste the column with the email addresses.
How do I see the entire list of members?
(where listname is replaced by the name of your list)
There is an option to view all list members, provided that you are a member of the list. Some list owners may choose to keep this private to only list owners.
If you are a list owner, there are two other ways you can also view your subscribers. The first would be to go to your administrative page at
where “listname” is replaced by the name of your list, and click on Membership Management. Here you can view all members alphabetically. If you need to view all members on one page, you can change the setting on the General Options page:
“Maximum number of members to show on one page of the Membership List.” to any number higher than the number of subscribers you have.
The other option would be to email the following command in plain text to email@example.com, where listname is replaced by your listname. (Note: words in “<>”s signify REQUIRED items and words in “” denote OPTIONAL items. Do not include the “<>”s or “”s when you use the commands.)
who password [address=<address>]
See the non-hidden members of this mailing list: The roster is limited to list members only, and you must supply your membership password to retrieve it. If you’re posting from an address other than your membership address, specify your membership address with`address=<address>’ (no brackets around the email address, and no quotes!). If you provide the list’s admin or moderator password, hidden members will be included.
How do I see the entire list of members on the Membership Management page?
By default, list members are listed alphabetically, with a maximum of 30 members per page.
If you would like to view all members at once, you can change that setting on the “General Options” page. Take a look at the setting: Maximum number of members to show on one page of the Membership List.
Change the number in this field to any number higher than the number of subscribers you have, save your settings, an you will be able to view all subscribers on one page.
Why are my message header and footer appearing as attachments?
The display of the footer depends on the email client being used to view the message and also whether or not there are any attachments on the message. If Mailman receives a message with MIME parts (generally attachments such as Word files but could be an html or rich text formatted message without any attachments), the header and footer will be added as additional MIME parts. How those are displayed, however, will depend on the email client you are using to view them.
Unix Pine: header appears as message body (although it is also labeled as a MIME part); body appears as attachment (although it is also displayed as part of the body); the footer appears as attachment (although it is also displayed as part of the body)
Outlook: message header not displayed or attached; message body is in the body; footer is an attachment.
Gmail: displays message header, body, and footer all as part of the message body with no indication of any attachments.
The easiest solution to this problem is to send plain text messages to your list.
Can people add logos to their headers/footers with Mailman?
Unfortunately this is not an option through Mailman. Text and URLs may be added, but there is no logo functionality.
How do I tell subscribers what their list password is when they forget it?
As a list owner, there is no way for you to look up a subscriber’s password. You can, however, direct them to the list’s information page at:
where listname is replaced with the actual name of your list.
Under the list’s Subscribers section, there will be an “Unsubscribe or edit options” button next to which is a space to enter an email address. The subscriber should enter his email address and click on the button. They will then see the option of having their password sent to them via email.
How do I delete a Mailman list that I own?
Visit your administrative page at
where listname is replaced with the name of your list. In the upper right-hand corner you will see a link for “Delete this mailing list”. The next page will require the administrative password to delete the list.
How do I create a list where only owners and moderators can post?
In order to do this, you must make sure that subscribers and non-subscribers cannot post. This will leave only the owners and moderators.
To reject mail from non-subscribers, first go to your list’s administration pages at:
where listname is the actual name of your list and enter your list administrator password. Click on “Privacy Options,” and then at the next page, click on “Sender Filters.”
In the Non-member filter section, scroll down to the line that says “Action to take for postings from non-members for which no explicit action is defined.” “Reject” and “Discard” will both prevent the mail from going to the list, but “Reject” will send a notice to the sender, whereas “Discard” will be silent. Do not submit your changes yet, but do stay on this page.
You will have to do a little more work to block mail from subscribers. There is no explicit way to do this, but there is a workaround. You can make all the subscribers moderated, then define what to do with mail from moderated subscribers.
To make all members moderated, go to the top of the “Sender Filters” page. Select “Yes” for the “default_member_moderation” option, so that new members are automatically set to “mod” status. The “member_moderation_action” option will allow you to choose what you do with the mail sent by subscribers. After making your choice, scroll to the bottom of the page and hit “Submit Your Changes”.
If your list already has subscribers, you should make sure that they are also set to “mod” status. Go to “Membership Management.” Under “Additional Member Tasks,” select the button that says “On” to set everyone’s moderation bit and then click “Submit Your Changes.” This will set all current subscribers to “mod” status.
If the owners and moderators are also subscribed to the list, you will need to change their moderation status. You can do so on the Membership List under Membership Management. Find each owner’s or moderator’s email address and uncheck the “mod” box. Click on the “Submit Your Changes” button before moving on to a new screen. If the owners or moderators are not subscribed to the list, follow the links to “Privacy Options” and then “Sender filters” and enter their email addresses in the “accept_these_nonmembers” field. When finished, submit your changes.
Your list is now configured so that only owners and moderators can freely post to your list.
How do I create and manage moderated lists?
Mailman has the ability to hold messages for owner or moderator approval prior to distributing them to list subscribers. Moderation is not a list-wide setting, but rather a per-user setting. This means that you can choose who can send messages directly to the list, and who has to wait for approval. If you prefer to have all messages moderated, there are ways you can easily do this.
Go to your list’s administration pages at:
(where listname is replaced with the actual name of your list)
If you decide that you would like members to have their messages moderated by default, go to “Privacy Options” then “Sender Filters.” Locate the “default_member_moderation” setting and select “Yes.” Then choose the action you want taken on messages sent by members. The “member_moderation_action” setting has three options: Hold, Reject, and Discard. “Hold” will hold the message for approval by the owner/moderator. “Reject” and “Discard” will both prevent the message from reaching the list, but “Reject” will send a notification to the sender, whereas “Discard” will not.
You can also set moderation for messages from non-member addresses. The “generic_nonmember_action” setting gives you four options: Accept, Hold, Reject, Discard. “Accept” means no moderation (the message will be delivered to the list members without requiring owner approval). “Hold,” “Reject,” and “Discard” are the same as described above.
When you have finished making changes on this page, click the button at the bottom that reads “Submit Your Changes.”
If you have existing members that you would like to make moderated, go to “Membership Management.” This will bring you to a screen that lists all the members of your list. The “mod” option allows you to specify whether a member’s postings are moderated or not. If you would like to change the moderation setting for all members of the list, you can do so under “Additional Member Tasks” by selecting “Off” to set everybody to unmoderated, or “On” to make everybody moderated. After selecting the option you want, click the “Set” button. This changes everyone’s moderation option, including the list owners if they are subscribed, so don’t forget to turn off moderation for your own address by unchecking the “mod” box next to the owners’ addresses and submitting your changes.
To manage a moderated list, you should go to your list’s administration pages, then click on the link in the upper right: “Tend to pending moderator requests.” Or you can access the pending moderator requests by going directly to:
where listname is replaced with the actual name of your list.
How do I change where replies to my list are sent?
As a Mailman list owner, you can configure your list so that replies to messages are directed to either the original sender, the entire list, or to a specific email address. The location you choose will depend on the type of list you want to have.
Replies directed to the original sender will cut down on list traffic. This may be the setting you prefer if you want to have an “announcement” type list.
Replies directed to the entire list will promote list discussions. This increases the amount of traffic on the list but it allows everybody to see the discussions.
Replies directed to an explicit address are good for announcement type lists with a parallel discussion type list. If this is the type of list you would like to have, select “Explicit address” and set the “Reply-To:” address setting to the discussion list address.
All of these settings can be found on the list administration page at:
where listname is replaced by the actual name of your list.
You will find the “Reply-To” settings in the “General Options” section under “Reply-To: header munging”.
How do I stop messages from sending (spam, mailing loop, etc.)?
If you need to quickly stop messages from being sent out to your list due to abuse or a mailing loop, log into the administrative pages for your list at:
where listname is the name of your list.
Under “General Options” scroll down to the bottom of the page and look for the section titled “Additional settings”. The first option under this section should be “emergency”. Set this to “Yes” and submit your changes to start emergency moderation.
When this option is set, all mail sent to the list will be held for moderation. When the problem has been resolved, you can allow your list operation to go back to normal by going back and changing this option back to “No”.
Can I use email commands to interact with the Mailman server?
Mailman has a limited set of commands that it will recognize via email. The majority of Mailman’s options are available exclusively by the Web interface.
Commands should be sent to firstname.lastname@example.org (where listname is replaced with the name of the list).
About the descriptions – words in “<>”s signify REQUIRED items and words in “” denote OPTIONAL items. Do not include the “<>”s or “”s when you use the commands.
The following commands are valid:
Confirm an action. The confirmation-string is required and should be supplied by a mailback confirmation notice.
Stop processing commands. Use this if your mail program automatically adds a signature file.
Print this help message.
Get information about this mailing list.
See a list of the public mailing lists on this GNU Mailman server.
password [<oldpassword> <newpassword>] [address=<address>]
Retrieve or change your password. With no arguments, this returns your current password. With arguments <oldpassword> and <newpassword> you can change your password.
If you’re posting from an address other than your membership address, specify your membership address with `address=<address>’ (no brackets around the email address, and no quotes!). Note that in this case the response is always sent to the subscribed address.
Set or view your membership options. Use `set help’ (without the quotes) to get a more detailed list of the options you can change. Use `set show’ (without the quotes) to view your current option settings.
subscribe [password] [digest|nodigest] [address=<address>]
Subscribe to this mailing list. Your password must be given to unsubscribe or change your options, but if you omit the password, one will be generated for you. You may be periodically reminded of your password. The next argument may be either: `nodigest’ or `digest’ (no quotes!). If you wish to subscribe an address other than the address you sent this request from, you may specify `address=<address>’ (no brackets around the email address, and no quotes!)
unsubscribe [password] [address=<address>]
Unsubscribe from the mailing list. If given, your password must match your current password. If omitted, a confirmation email will be sent to the unsubscribing address. If you wish to unsubscribe an address other than the address you sent this request from, you may specify`address=<address>’ (no brackets around the email address, and no quotes!)
who password [address=<address>]
See the non-hidden members of this mailing list. The roster is limited to list members only, and you must supply your membership password to retrieve it. If you’re posting from an address other than your membership address, specify your membership address with`address=<address>’ (no brackets around the email address, and noquotes!). If you provide the list’s admin or moderator password, hidden members will be included.
How do I subscribe to a Mailman list?
To access a private list, you will need to know the exact list name. You can type the name in the URL like this:
where listname is the list’s actual name
For example, if you want to access the list information page for the list demo, you would go to:
Once you have accessed the list’s information page, you will see a section that will allow you to subscribe to the list. Enter your email address and create a password. The password that you select should be only for this mailing list.
When you fill out the form, you will be given the option of receiving mail from the list in digest format. The digest format will result in you receiving a single message from the list each day with all of the messages bunched together rather than receiving them individually. If you later decide you want to change your digest option, you can do so.
Once you have filled in the information requested in the “Subscribing” section, click on the “Subscribe” button. If the list has been set up to require owner approval for subscriptions, you will have to wait until the list owner approves your subscription request. Otherwise, Mailman will send an email message to your email address. The message that you receive will ask you to confirm your subscription request. This helps to prevent other people from adding you to a list without your permission. When you receive the confirmation request, simply reply to the message. You do not have to add any additional text and you should not modify the subject line.
After successfully subscribing to the list, Mailman will probably send you a welcome message (list owners can configure their list so that welcome messages are not sent). The message will include the URL that will direct you to the list’s information page, a URL that will direct you to your personal settings page, and your list password. You should keep the welcome message for future referral. You will need the information contained in it if you ever want to modify your personal settings on the list or unsubscribe.
How can I find my subscriber password?
To get your password for a Mailman list, go to the list’s information page at:
where listname is replaced with the list’s actual name.
Under the list’s Subscribers section you will see an “Unsubscribe or edit options” button next to which you can enter your email address. Enter the email address with which you are subscribed to the list and click on the button. This will take you to the list’s “Membership Configuration” page where you can change your membership options, unsubscribe to the list, or request a password reminder. By clicking on the “Remind” button at the bottom of the page, your list password will be emailed to you.