diff --git a/reveal/sysadmin.html b/reveal/sysadmin.html
index d208b92..7103141 100644
--- a/reveal/sysadmin.html
+++ b/reveal/sysadmin.html
@@ -154,14 +154,24 @@ Modifier une unité
 </section>
 
 <section>
-<h2>Postfix</h2>
-# apt install postfix
-
-Configuration process : /etc/postfix/master.cf
-Configuration options : /etc/postfix/main.cf
-
-# vim main.cf
-
+  <section>
+    <h2>Postfix</h2>
+  </section>
+  <section>
+    <h3>Installation</h3>
+    <pre><code data-trim class="hljs nohighlight">
+      # apt install postfix
+    </code></pre>
+    <h3>Configuration</h3>
+    <ul>
+      <li>process : /etc/postfix/master.cf</li>
+      <li>options : /etc/postfix/main.cf</li>
+    </ul>
+  </section>
+  <section>
+  <pre>
+<code># vim main.cf</code>
+<code data-trim style="max-height: 500px">
 smtpd_banner = $myhostname ESMTP mail server
 biff = no
 append_dot_mydomain = no
@@ -177,7 +187,12 @@ recipient_delimiter = +
 inet_interfaces = all
 inet_protocols = ipv4
 disable_vrfy_command = yes
+</code></pre>
+</section>
 
+<section>
+<pre>
+<code class="hljs nohighlight" data-trim style="max-height: 500px">
 # date | mail -s test jdoe@example.com
 # mailq
 # qshape deferred
@@ -187,7 +202,10 @@ disable_vrfy_command = yes
 # postsuper -r < queue_id >
 # postsuper -r ALL
 
-# mailq | tail -n +2 | awk 'BEGIN { RS = "" } /example\.com$/ { print $1 }' | tr -d '*!' | postsuper -d -
+# mailq | tail -n +2 | \
+    awk 'BEGIN { RS = "" } /example\.com$/ { print $1 }' | \
+    tr -d '*!' | postsuper -d -
+</code></pre>
 </section>
 
 <section>