</listitem>
</varlistentry>
<varlistentry>
+<term>email</term>
+<listitem>
+<para>If set, use email for communication rather than TCP or UDP.
+The value is used as the target mail address.</para>
+</listitem>
+</varlistentry>
+<varlistentry>
<term>tcp</term>
<listitem>
<para>If "true", use TCP for communication; if "false", use UDP.