Mailman delivers messages to users via two modes. List members can elect to receive postings in bundles called digests one or a few times a day, or they can receive messages immediately whenever the message is posted to the list. This latter delivery mode is also called non-digest delivery. There are two administrative categories available for separately controlling digest and non-digest delivery. You can even disable one or the other forms of delivery (but not both).
Both kinds of delivery can have list-specific headers and footers added to them which can contain other useful information you want your list members to see. For example, you can include instructions for unsubscribing, or a url to the lists digest, or any other information.
Non-digest deliveries can also be personalized which means certain parts of the message can contain information tailored to the member receiving the message. For example, the To: header will contain the address of the member when deliveries are personalized. Footers and headers can contain personalized information as well, such as a link to the individual user's options page.
In addition, personalized messages will contain extra information that Mailman can use to unambiguously track bounces from members. Ordinarily, Mailman does some pattern recognition on bounce messages to determine list members whose addresses are no longer valid, but because of the vagaries of mail systems, and the countless forwards people can put in place, it's often the case that bounce messages don't contain any useful information in them. Personalized messages avoid this problem by encoding information in certain headers that unambiguously identify the recipient of a message. If that message bounces, Mailman will know exactly which member it was intended for.
Note that because personalization requires extra system resources, it must be enabled by the site administrator before you can choose it.
Here are the variables which control non-digest delivery:
See below for more information on what can go in the headers and footers. If you leave this text box empty, no header will be added.
Headers and footers can contain any text you want. For non-English
lists, the headers and footers can contain any character in the
character set of the list's preferred language. The headers and
footers can also contain substitution variables which Mailman
will fill in with information taken from the mailing list. These
substitutions are in Python string interpolation format, where
something like %(list_name)s
is substituted with he name of
the mailing list. Note that the trailing "s" is
required2.
For example, a footer containing the following text:
This is the \%(list_name)s mailing list Description: \%(description)s
might get attached to postings like so:
This is the Example mailing list Description: An example of Mailman mailing lists
Here is the list of substitution variables available for your headers and footers:
real_name
configuration variable
in the General options category.
listinfo/%(list_name)s
to yield the
general list information page for the mailing list.
.cgi
, or something else depending on how your site
is configured.
Note that real_name
, host_name
, description
, and
info
substitution variables take their values from the list
configuration variables of the same name.
When personalization is enabled, the following substitution variables are also available:
$list_name
or
${list_name}
would be substituted with the mailing list's
name. Ask your site administrator if they've configured your list this
way.
_internal_name
is
equivalent.
user_address
and user_delivered_to
is used, but it's
important to remember that they can be different. When they're
different, Mailman always uses the lower case address as the key
to the member's subscription information, but it always delivers
messages to the case-preserved version.