diff --git a/Doc/Sdi/Ref/Fig/postfix_intern.png b/Doc/Sdi/Ref/Fig/postfix_intern.png
new file mode 100644
index 0000000000000000000000000000000000000000..f4de8cc2c51f712dff0c990163c5ccfcc8a0b682
Binary files /dev/null and b/Doc/Sdi/Ref/Fig/postfix_intern.png differ
diff --git a/Doc/Sdi/mail.xml b/Doc/Sdi/mail.xml
index d6c6fa296af70510fd54a0a9b97a024c7ce02a78..feb1465c911462861ef3fceed8b5ad002f85f2f5 100644
--- a/Doc/Sdi/mail.xml
+++ b/Doc/Sdi/mail.xml
@@ -41,8 +41,9 @@
       </listitem>
 
       <listitem>
-        <para xml:lang="de"><link xlink:href="http://www.admin-magazin.de/Online-Artikel/Postfix-einrichten-und-absichern">Postfix einrichten und
-        absichern</link></para>
+        <para xml:lang="de"><link
+        xlink:href="http://www.admin-magazin.de/Online-Artikel/Postfix-einrichten-und-absichern">Postfix
+        einrichten und absichern</link></para>
       </listitem>
 
       <listitem>
@@ -115,6 +116,10 @@
     <para>Our aim is to install and configure the <acronym>MTA</acronym>
     Postfix. Sending, delivering and receiving an email works like:</para>
 
+    <para/>
+
+    <para/>
+
     <informalfigure>
       <mediaobject>
         <imageobject>
@@ -126,8 +131,9 @@
     <section xml:id="sdiMailInstallSendLocalUsers">
       <title>Install and send to local Users</title>
 
-      <para>Install postfix. If asked use "Internet site". Stay with the defaults. Later it is
-      maybe needed to install extra postfix-* packages.</para>
+      <para>Install postfix. If asked use "Internet site". Stay with the
+      defaults. Later it is maybe needed to install extra postfix-*
+      packages.</para>
 
       <programlisting language="none">apt-get install postfix</programlisting>
 
@@ -192,8 +198,8 @@
         </listitem>
 
         <listitem>
-          <para>install a <acronym>sasl</acronym> implementation
-          (look at <command>dovecot</command>)</para>
+          <para>install a <acronym>sasl</acronym> implementation (look at
+          <command>dovecot</command>)</para>
 
           <itemizedlist>
             <listitem>
@@ -291,7 +297,7 @@
 
         <listitem>
           <para>both connections should be secured via <xref
-          linkend="glo_TLS"/>. Look in your mail.log to verify this </para>
+          linkend="glo_TLS"/>. Look in your mail.log to verify this</para>
         </listitem>
       </itemizedlist>
     </section>
@@ -300,7 +306,6 @@
       <title>Spam and Virus defense</title>
 
       <para><itemizedlist>
-
           <listitem>
             <para>Now we will use the smtpd_*_restrictions in the
             <filename>main.cf</filename>. This are one key element to make
@@ -318,8 +323,9 @@
 
             <itemizedlist>
               <listitem>
-                <para>test sending emails using telnet or a
-                <acronym>MUA</acronym> to your virtual email address</para>
+                <para>test sending emails using telnet (from your host
+                maschine) or a <acronym>MUA</acronym> to your virtual email
+                address</para>
 
                 <tip>
                   <para>this needs to be done without authentication</para>
@@ -415,17 +421,18 @@
       </section>
 
       <section xml:id="sdiSectSpf">
-        <title><acronym>SPF</acronym></title>
+        <title><acronym>SPF (optional)</acronym></title>
 
         <para>Where are plenty of Spam prevention techniques like
         <acronym>DMARC</acronym>, <acronym>DKIM</acronym>,
         <acronym>DANE</acronym>, Postscreen and other Policy Deamons (e.g.
-        <link xlink:href="http://www.policyd-weight.org/">policyd-weight</link>). Good Providers use most
-        of them. We can't test all of them in SDI. They help to detect spam
-        but not scam. So if Spammers use meine-dt-bank.de to obtain your
-        PIN/TAN by a scam this mails could also use SPF or DKIM for there
-        domain. So this techniques won't help there. The user is still
-        responsible to detect such scams.</para>
+        <link
+        xlink:href="http://www.policyd-weight.org/">policyd-weight</link>).
+        Good Providers use most of them. We can't test all of them in SDI.
+        They help to detect spam but not scam. So if Spammers use
+        meine-dt-bank.de to obtain your PIN/TAN by a scam this mails could
+        also use SPF or DKIM for there domain. So this techniques won't help
+        there. The user is still responsible to detect such scams.</para>
 
         <para/>