lfs-book/chapter01/subscribe.xml

<sect2>
<title>How to subscribe?</title>

<para>
Any of the above-mentioned mailinglists can be subscribed to by sending
an email to <ulink url="mailto:listar@linuxfromscratch.org">
listar@linuxfromscratch.org</ulink> and writing <emphasis>subscribe
listname</emphasis> as the subject header of the message.
</para>

<para>
Multiple lists at the same time can be subscribed to by using
one email. This is done by writing some junk as the subject
header, something that isn't a valid command like "hello". Then 
the subscribe commands need to be in the body of the message.
 The email will look 
like:
</para>

<blockquote><literallayout>

To: listar@linuxfromscratch.org
Subject: hello

subscribe lfs-discuss
subscribe lfs-apps
subscribe alfs-discuss

</literallayout></blockquote>

<para>
After the email is sent, the Listar program will reply with an
email requesting a confirmation of the subscription request. After
this confirmation email was sent back, Listar will send an
email again with the message that the user has been subscribed to the
list(s) along with an introduction message for that particular list.
</para>

</sect2>