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authorLaurent Bercot <ska-skaware@skarnet.org>2026-02-02 18:01:03 +0000
committerLaurent Bercot <ska-skaware@skarnet.org>2026-02-02 18:01:03 +0000
commit36491e787c8be5b32b93f5c3b20edd9aa9d4c4e9 (patch)
tree101b8cf332eb050cda394e11003cb3ee5dc2605b /doc
parent541b3256968eae128abd35e762f3e3a81885fa7c (diff)
downloadsmtpd-starttls-proxy-36491e787c8be5b32b93f5c3b20edd9aa9d4c4e9.tar.gz
More qmail-smtpc stuff
Diffstat (limited to 'doc')
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-rw-r--r--doc/qmail-smtpc.html79
-rw-r--r--doc/upgrade.html1
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diff --git a/doc/index.html b/doc/index.html
index fc355d7..8dfae68 100644
--- a/doc/index.html
+++ b/doc/index.html
@@ -39,6 +39,9 @@ requirement if you link against the shared version of the skalibs
library. </li>
<li> <a href="//skarnet.org/software/s6/">s6</a> version
2.14.0.1 or later. It's a build-time and run-time requirement. </li>
+ <li> <a href="//skarnet.org/software/s6-dns/">s6-dns</a> version
+2.4.1.1 or later. It's a build-time requirement. It's also a run-time requirement
+if you link against the shared version of the s6-dns library. </li>
<li> <a href="//skarnet.org/software/s6-networking/">s6-networking</a> version
2.7.2.1 or later. It's a build-time and run-time requirement. </li>
</ul>
diff --git a/doc/qmail-smtpc.html b/doc/qmail-smtpc.html
new file mode 100644
index 0000000..47ee375
--- /dev/null
+++ b/doc/qmail-smtpc.html
@@ -0,0 +1,79 @@
+<html>
+ <head>
+ <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+ <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
+ <meta http-equiv="Content-Language" content="en" />
+ <title>smtpd-starttls-proxy: the qmail-smtpc program</title>
+ <meta name="Description" content="smtpd-starttls-proxy: the qmail-smtpc program" />
+ <meta name="Keywords" content="smtp client qmail qmail-remote" />
+ <!-- <link rel="stylesheet" type="text/css" href="//skarnet.org/default.css" /> -->
+ </head>
+<body>
+
+<p>
+<a href="index.html">smtpd-starttls-proxy</a><br />
+<a href="//skarnet.org/software/">Software</a><br />
+<a href="//skarnet.org/">skarnet.org</a>
+</p>
+
+<h1> The <tt>qmail-smtpc</tt> program </h1>
+
+<p>
+<tt>qmail-smtpc</tt> is an SMTP client, meant to be used as a drop-in
+replacement to
+<a href="http://qmail.org/man/man8/qmail-remote.html">qmail-remote</a>.
+</p>
+
+<p>
+ It is not meant to be invoked directly by the user; it only makes sense
+in the context of a qmail, netqmail or notqmail installation.
+</p>
+
+<h2> Interface </h2>
+
+<p>
+ <tt>qmail-smtpc</tt> follows the exact same interface as
+<a href="http://qmail.org/man/man8/qmail-remote.html">qmail-remote</a>.
+The binary can literally be renamed <tt>qmail-remote</tt> then dropped
+in <tt>/var/qmail/bin</tt> in place of the stock <tt>qmail-remote</tt>
+program. With some patches, it can also be used by setting the
+QMAILREMOTE environment variable to the path where <tt>qmail-smtpc</tt>
+is installed.
+</p>
+
+<h2> Differences with qmail-remote </h2>
+
+<ul>
+ <li> If the underlying OS and <a href="//skarnet.org/software/skalibs/">skalibs</a>
+support IPv6, then <tt>qmail-smtpc</tt> does as well, and use IPv4 and IPv6
+addresses indiscriminately when connecting to an MX. </li>
+ <li> It speaks ESMTP and will use STARTTLS if the server supports it. </li>
+</ul>
+
+<h2> Control files </h2>
+
+<p>
+ qmail-smtpc uses a few extra control files in <tt>/var/qmail/control</tt>:
+<p>
+
+<dl>
+ <dt> <tt>trustanchors</tt> </dt>
+ <dd> Contains the path to the certificates for known trust anchors for X.509
+certificate validation. If the path ends with a slash, like <tt>/etc/ssl/certs/</tt>,
+then it is interpreted as a directory containing hashes to the certificates. If
+it does not, like <tt>/etc/ssl/cert.pem</tt>, then it is interpreted as a big
+PEM file containing all the trust anchors. If the file is nonexistent or empty,
+or only contains a newline, then STARTTLS is not attempted. </dd>
+ <dt> <tt>clientcert</tt> </dt>
+ <dd> If this file exists and is nonempty, it must contain the path to a client
+certificate. This certificate will be sent to the server during a TLS negotiation.
+This is useful in certain setups requiring client authentication. </dd>
+ <dt> <tt>clientkey</tt> </dt>
+ <dd> This file must be used in conjunction with <tt>clientcert</tt>. It contains
+the path to the private key used to sign the client certificate. Note that access
+to the private key file should be as restricted as possible, but the <tt>qmailr</tt>
+user (or whatever user <tt>qmail-smtpc</tt> runs as) must be able to read it. </dd>
+</dl>
+
+</body>
+</html>
diff --git a/doc/upgrade.html b/doc/upgrade.html
index 7aa6237..1dba5fc 100644
--- a/doc/upgrade.html
+++ b/doc/upgrade.html
@@ -25,6 +25,7 @@
dependency bumped to 2.14.5.1 </li>
<li> <a href="//skarnet.org/software/s6/">s6</a>
dependency bumped to 2.14.0.1 </li>
+ <li> New dependency: <a href="//skarnet.org/software/s6-dns/">s6-dns</a> 2.4.1.1 </li>
<li> <a href="//skarnet.org/software/s6-networking/">s6-networking</a>
dependency bumped to 2.7.2.1 and made mandatory. </li>
</ul>