<?xml version="1.0"?>

<!--
  Copyright (C) 2006, 2007 Anton Yuzhaninov
  Copyright (C) Nginx, Inc.
  -->

<!DOCTYPE module SYSTEM "../../../../dtd/module.dtd">

<module name="Module ngx_mail_pop3_module"
        link="/en/docs/mail/ngx_mail_pop3_module.html"
        lang="en"
        rev="1">

<section id="directives" name="Directives">

<directive name="pop3_auth">
<syntax><value>method</value> ...</syntax>
<default>plain</default>
<context>mail</context>
<context>server</context>

<para>
Sets permitted methods of authentication for POP3 clients.
Supported methods are:
<list type="tag">

<tag-name><literal>plain</literal></tag-name>
<tag-desc>
<link url="http://tools.ietf.org/html/rfc1939">USER/PASS</link>,
<link url="http://tools.ietf.org/html/rfc4616">AUTH PLAIN</link>,
<link url="http://tools.ietf.org/html/draft-murchison-sasl-login-00">AUTH LOGIN</link>.
It is not possible to disable this methods.
</tag-desc>

<tag-name><literal>apop</literal></tag-name>
<tag-desc>
<link url="http://tools.ietf.org/html/rfc1939">APOP</link>.
In order for this method to work, the password must be stored unencrypted.
</tag-desc>

<tag-name><literal>cram-md5</literal></tag-name>
<tag-desc>
<link url="http://tools.ietf.org/html/rfc2195">AUTH CRAM-MD5</link>.
In order for this method to work, the password must be stored unencrypted.
</tag-desc>

</list>
</para>

</directive>


<directive name="pop3_capabilities">
<syntax><value>extension</value> ...</syntax>
<default>TOP USER UIDL</default>
<context>mail</context>
<context>server</context>

<para>
Allows to specify the
<link url="http://tools.ietf.org/html/rfc2449">POP3 protocol</link>
extensions list to be passed to the client upon
issuing the <literal>CAPA</literal> command.

Authentication methods specified in the <link id="pop3_auth"/> and
(<link url="http://tools.ietf.org/html/rfc2449">SASL</link> extension) and
<link url="http://tools.ietf.org/html/rfc2595">STLS</link> directives,
are automatically added to this list if the
<link doc="ngx_mail_ssl_module.xml" id="starttls"/> directive is enabled.
</para>

<para>
It makes sense to specify extensions
supported by POP3 backends
to which clients are proxied (if this extensions are related to commands
used after the authentication, when nginx transparently proxies the client
connection to the backend).
</para>

<para>
The current list of standardized extensions is published at the
<link url="http://www.iana.org/assignments/pop3-extension-mechanism">www.iana.org</link>.
</para>

</directive>

</section>

</module>