1. Introduction to Ezmlm
Ezmlm is a fast and secure modern mailing list manager. It was written in C by Dan J. Bernstein for speed and reliability. It is augmented by the ruggedness of the qmail delivery mechanism upon which it is built.
This document is intended for list owners and shows you how to configure your mailing list. If you are looking for information on how to subscribe or be removed from an ezmlm list please click the following link: Subscribing/Unsubscribing from ezmlm mail lists.
2. Getting started
Figure images/page1.gif [Homepage of your mailing list account]
3. Mailing List Configuration
Config' from the mailing list homepage. You will then see the following web page:
Figure images/config.gif [Configuration page for the mailing list.]
Your mailing list preferences are set using the configuration manager.
Some options need to be selected first and these changes saved BEFORE secondary options appear in boxes at the foot of the page. Further editing will then be necessary to complete the setup. This is caused by the underlying programme running the ezmlm software. In the following sections this effect is highlighted where it occurs.
4. Controlling who may subscribe and unsubscribe
Figure images/subscriptions.gif [Subscriptions configuration panel]
People are required to confirm that they wish to subscribe to or unsubscribe from a mailing list when they make a request. There is, however, no confirmation process when members are subscribed or unsubscribed by the list administrator via the web interface. List administrators will need to send out a welcome message if they wish the new members to receive one.
When a list has subscription moderation turned on and someone requests subscription to the list they will first be asked to confirm their request then it will be passed on to the subscription moderators for them to accept or reject.
4.1. Allow subscribe and unsubscribe requests
If you want people to be able to request to join or leave your mailing list then you will need to select option 1. If you do not select this option then any requests to join or leave will be rejected.
4.2. Moderation of subscribe requests
If you want to control who can join your mailing list, select options 1 and 2.
Please Note: Option 2 sets moderation of subscriptions only. In most cases you should let people unsubscribe from your list if they really want to.
5. Controlling who may post to a list
You can control who posts to your mailing list in several ways. Some options are dependent on each other so combining options in the web interface may not always give exactly what you expect.
Figure images/posting.gif [Posting configuration panel]
Make changesbutton at the foot of the page.
5.1. Open access
If you do not select any of the Posting options listed above then the list will be completely open to posts by the general public.
5.2. Blocking certain addresses
If you have a mailing list where anyone can post, or possibly posting is limited to subscribers, you may wish to block certain addresses that are continually causing trouble on the list or posting large quantities of unwanted spam mail. In this case you can turn on option 2 above and put their addresses into the Deny Posters list.
This is not a complete solution as it is very easy to obtain a new email address to post from but it can be useful in some situations.
5.3. Subscribers + allowed posters only
Commonly list owners want to limit posts to subscribers only. To setup this configuration select option 5 from the list above. It can be combined with option 2, to deny posting rights for certain members.
In Oxford people often have more than one email address (e.g. a college address and a departmental address). A good working solution to this problem is to add one form into the subscriber list and the other into the Allow Posters list so that the list member does not need to worry about which address they are posting from, either would be accepted by the server. Only the address in the Subscriber list will receive mail from the list.
5.4. All posts moderated
If you need to check all posts to the list before allowing them to be posted you should turn on option 3 in the Postings panel. This means all messages, no matter who they are from, are sent to the moderators. You must specify at least one email address in the moderators list otherwise postings to the list will not be moderated.
For details on how the moderation system works see Moderating messages and requests.
You can also completely block messages from specified users by using the Deny Posters list. In which case posts from those addresses would be silently dropped and not passed onto the moderators.
5.5. Subscribers + others moderated
You may want to allow subscribers to post without any moderation and also allow non-subscribers to post but with moderation to block unwanted messages, such as spam. In this case you should select options 3 and 5 together.
As above, you can also completely block messages from specified users by using the Deny Posters list. In which case posts from those addresses would be silently dropped and not passed onto the moderators
5.6. Moderators only
If your list is intended to be used for announcements only, e.g. a college official mailing list, then you may want to limit posting rights to only those email addresses in the moderators list. If you are not using subscription moderation as well as posting moderation then the moderators will not receive any moderation requests other than for their own messages.
To activate the message moderation system select option 3 and also select option 4 to set up moderator posting only. In this situation the options 2 and 5 will have no effect. This is similar to the Majordomo restrict lists, which creates a small group of allowed posters.
Moderators will be required to self-moderate their posts. This is a security measure to prevent spoofing of email addresses. In self-moderation only the original sender receives a copy of the post instead of all the moderators. Moderation is very simple and is described in Moderating messages and requests.
If you intend to moderate subscriptions as well as posting and you do not want those on your restricted posters list to receive subscription moderation requests then the best solution is to select option 1 instead. See below for details.
5.7. Allowed posters only
This case is similar to the Majordomo restricted poster list. Only those addresses in the Allow Posters list will be able to post to the mailing list.
To set up this situation select options 1, 3 and 4. The configuration system will automatically force options 3 and 4 to be selected if you select option 1 alone.
In this situation those allowed posters will be required to self-moderate their posts to the mailing list as explained in the section above Moderators only. If you turn on subscription moderation those moderation requests will be directed to email addresses in the moderator list rather than the allowed posters list. People on the allowed posters list will not see any moderation requests other than for their own posts as anyone not in the allowed posters list will be blocked.
6. Moderating messages and requests
Moderation of subscription requests and posts is relatively simple. The moderator receives a message asking them to check the request, which is quoted in the message. They should either reply to the From address - to reject the message (it has the reject word in the address) or to the Reply-To address - to accept the message (it has accept in the address). Most email software will automatically select the Reply-To address so it is very simple to accept a message, which will likely be the most frequent case.
If moderators wish to get help they can send a message to
and it will return a general help page on how to moderate
There is a default time limit for moderation of messages. This is set to 120 hours. After this time any requests that have not been accepted or rejected, will automatically be considered to have been rejected. The time allowed can be set to any whole number of hours between 24 and 240 through the Options panel.
7. Managing obsolete email addresses
One of the problems with mailing lists is that they can quickly become obsolete as subscribers change their email address and do not remove old addresses from lists they are subscribed to. Ezmlm has a method to monitor bounced emails and can remove addresses from which emails regularly return.
Ezmlm uses the subscriber address and message number (encoded within the sender address) to track which message have bounced for which recipient. Since messages can bounce for a variety of reasons, ezmlm does not remove a subscriber from the list immediately. Instead it waits 12 days after the first bounce, then sends a warning message to the subscriber. The warning message lists the numbers of the messages missed. The user can retrieve these from the archive (if this feature has been enabled). If the warning message again bounces back, ezmlm waits another 12 days, then sends a probe message. If this probe message bounces the email address is removed from the subscriber database. This mechanism guarantees that a subscriber will not be removed due to a temporary error, while assuring that all non-existent or permanently failing addresses are removed.
Please Note: Subscribers receiving warning messages and the probe message do not need to do anything with them. Ezmlm is just checking to see if their address will receive its test messages.
8. Archiving and Digests
Digests are not currently supported. Ezmlm maillist archives are available through the email interface. A guide on how to use the archive feature is given in the Ezmlm formal guide. You can also view a list of publically available maillists.
9. Filtering Spam
Spam can be very annoying to subscribers, moderators, and owners of maillists. Subscribers stand an increased risk of receive copies of spam even if they have taken good care over the configuration and management of their own email account; Moderators can be swamped with moderation messages relating to spam that has arrived at the list address; Owners may receive spam that has been detected as (un)subscription requests, complaints from list users, and complaints from third parties who have ended up involved.
9.1. Basic List Configuration to Block Spam
Figure images/settings.gif [Settings configuration panel]
In the Settings panel there are two Spam filtering options that control how the Oxmail spam scoring system is used to reduce spam on your maillist: Enable and Level. By default these options ignore spam scoring - all mail goes through. This is to ensure that a newly create list will faithfully transmit all posts.
A moderate setting that will significantly reduce spam is to tick the Enable option, and leave the Level at the default value of 5.
9.2. Other Options for Controlling Spam
10. Other Options
Figure images/others_panel.gif ['Others' configuration panel]
Further options are also available under the settings section following on from the Others panel.
10.1. Subject prefix
Ezmlm can be configured to insert a prefix onto the
subject of any new message sent to the mailing list. To
use this facility select option 1( Outgoing
message subject will have a prefix) in the
Others panel. Save your changes by
Make changes button at the
foot of the page. The system automatically adds the
default [listname] into the Subject
Prefix box. Alternatively you can insert your
own a short prefix into the Subject Prefix,
Save any changes you make.
10.2. Message Size
There is a maximum size of 10MB for all messages passing
through the Oxford EZMLM system. This is therefore the
maximum value you can set for maillist posts. The
default maximum size is 3Mb and minimum size of 2 bytes.
To increase or decrease these values select option 3 in
the Others panel and type in new maximum or
minimum values under the Settings section. Save your
changes using the
Make Changes button.
10.3. Trailers for messages
You may want to add unsubscription details or other
information to the end of each post. In order to achieve
this, select option 2 in the Others panel.
You must now save your changes by pressing the
Make changes button, otherwise the
trailer trailer text file will not appear in the text
file list. Once the configuration file has been saved,
[Text Files] from the main menu. The
text files page will now appear and show
Trailer as an link. Click on
Trailer to edit the default text. The
trailer default text is shown below:
------------------------------------------------------- To unsubscribe, e-mail: [list name]-firstname.lastname@example.org For additional commands, e-mail: [list name]-email@example.com
10.4. MIME removal and rejection
Ezmlm provides the ability to strip or block unwanted MIME-type parts of emails. For instance if a user sends a html and text only versions, you can specify that the html version is stripped from the email. Your list members will only receive the plain text part of the email which all email software can handle. If there was only a html part and nothing else the message would be blocked (i.e. returned to sender) instead.
This can also be used to ensure people do not send binary attachments, such as large image files or viruses to your mailing list.
To activate this option you need to select Message blocking and stripping from the Others panel. At this point save your changes. Scroll down to the MIME types to strip from all outgoing mail box. This box will now contain the list of default MIME-types to be stripped or blocked from the mailing list. You can then edit this list as appropriate.
10.5. Headers to add and remove
Ezmlm allows you to add customized headers to all posts and to remove any occurences of specified headers sent through its system. This feature is always in operation, so to make use of it there is no need to turn on any special options. You could, for instance, add a specific Reply-To header to ensure people always reply directly to the list instead of the sender.
10.6. Using an Alias with the Maillist
In the Settings section of the configuration page, there is an option to allow an alias email address to be used with the maillist:
Figure images/alias-address.png [Shows the Allow alias to be used checkbox]
To use an alias to send email to a list, the checkbox should be ticked. This will disable the checking of whether the list address appears in the To: or Cc: header of messages sent to the list. Most lists will not need this option so it should be left unticked. Please note if you do select this option, you will increase the amount of spam email sent to your list.
To setup or change where a generic alias is routed, contact firstname.lastname@example.org
10.7. Nested Lists
Nesting enables an EZMLM list (the "child") to be subscribed to another EZMLM list (the "parent") so that an email sent to the parent list is sent to subscribers of the child list as well as subscribers of the parent list.
Nesting is not enabled by default, but you can request this by emailing email@example.com with the full address(es) of the child lists that you wish to nest.