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--></head><body><div class="refentry" title="preline"><a id="id339076" shape="rect"> </a><div class="titlepage"/><div class="refnamediv"><h2>Name</h2><p>preline — Prepend legacy mbox headers</p></div><div class="refsynopsisdiv" title="Synopsis"><h2>Synopsis</h2><div class="cmdsynopsis"><p><code class="command">@bindir@/preline</code>  {<em class="replaceable"><code>program</code></em>} [arg...]</p></div></div><div class="refsect1" title="DESCRIPTION"><a id="id338822" shape="rect"> </a><h2>DESCRIPTION</h2><p>
<span class="command"><strong>preline</strong></span> is a wrapper for <span class="command"><strong>program</strong></span>.
<span class="command"><strong>preline</strong></span> is usually invoked from
<code class="filename">$HOME/.courier</code>.
<span class="command"><strong>preline</strong></span> runs <span class="command"><strong>program</strong></span>,
together with any additional arguments
specified on the command line.
<span class="command"><strong>program</strong></span> then receives the message being delivered, with
some additional headers.
The additional headers come from the <code class="envar">UFLINE</code>,
<code class="envar">DTLINE</code>, and <code class="envar">RPLINE</code> environment variables.
These environment
variables are initialized by <span class="command"><strong>courierdeliver</strong></span>, which reads
and executes
commands from <span class="command"><strong>$HOME/.courier</strong></span>.
These environment variables contain
additional headers that should be added to every message that's delivered to a
local mailbox.</p><p>
<span class="command"><strong>preline</strong></span> must be used if <span class="command"><strong>program</strong></span>,
that is executed from
<code class="filename">$HOME/.courier</code> to deliver mail,
does not recognize these environment variables.
<code class="envar">UFLINE</code> contains the <code class="literal">From_</code> line,
<code class="envar">DTLINE</code> contains the
<code class="literal">Delivered-To:</code> header, and <code class="envar">RPLINE</code> contains the
<code class="literal">Return-Path:</code> header. If these headers are not present in
the message
that the program reads, you may end up with excessive resources being consumed
by mail loops or by malfunctioning software which expects to see
<code class="literal">From_</code> lines in all messages scheduled for local delivery
(such as <span class="command"><strong>procmail</strong></span>).</p></div><div class="refsect1" title="EXAMPLE"><a id="id373391" shape="rect"> </a><h2>EXAMPLE</h2><div class="informalexample"><pre class="programlisting" xml:space="preserve">
| @bindir@/preline /usr/bin/procmail
</pre></div><p>
This is the normal way to arrange for <span class="command"><strong>procmail</strong></span> to handle
local mail delivery.</p></div><div class="refsect1" title="SEE ALSO"><a id="id373417" shape="rect"> </a><h2>SEE ALSO</h2><p>
<a class="ulink" href="courierpop3d.html" target="_top" shape="rect"><span class="citerefentry"><span class="refentrytitle">courierpop3d</span>(8)</span></a>,
<a class="ulink" href="couriertcpd.html" target="_top" shape="rect"><span class="citerefentry"><span class="refentrytitle">couriertcpd</span>(8)</span></a>,
<a class="ulink" href="authlib/authlib.html" target="_top" shape="rect"><span class="citerefentry"><span class="refentrytitle">authlib</span>(7)</span></a>.</p></div></div></body></html>
