diff --git a/COPYING.DOC b/COPYING.DOC
--- a/COPYING.DOC
+++ b/COPYING.DOC
@@ -355,7 +355,7 @@
 of the GNU Free Documentation License from time to time.  Such new
 versions will be similar in spirit to the present version, but may
 differ in detail to address new problems or concerns.  See
-http://www.gnu.org/copyleft/.
+https://www.gnu.org/copyleft/.
 
 Each version of the License is given a distinguishing version number.
 If the Document specifies that a particular numbered version of this
diff --git a/doc/kmail2/configure.docbook b/doc/kmail2/configure.docbook
--- a/doc/kmail2/configure.docbook
+++ b/doc/kmail2/configure.docbook
@@ -550,8 +550,8 @@
 <term><guilabel>Input Field Below</guilabel></term>
 <listitem>
 <para>Use this field to enter an arbitrary X-Face string.
-Examples are available at <ulink url="http://ace.home.xs4all.nl/X-Faces/"
->http://ace.home.xs4all.nl/X-Faces/</ulink>
+Examples are available at <ulink url="https://ace.home.xs4all.nl/X-Faces/"
+>https://ace.home.xs4all.nl/X-Faces/</ulink>
 </para>
 </listitem>
 </varlistentry>
@@ -893,7 +893,7 @@
 is displayed in the window. This only applies to the separate message window, not to the embedded
 message preview pane.</para>
 <para>By default, <guilabel>Enable access key</guilabel> is enabled. Access keys allow you to use the keyboard keys for functions which would perhaps normally be done with the mouse, such as following links.
-  For more information on access keys please see <ulink url="http://docs.kde.org/stable/en/applications/konqueror/accesskeys.html">Access keys</ulink>.</para>
+  For more information on access keys please see <ulink url="https://docs.kde.org/stable/en/applications/konqueror/accesskeys.html">Access keys</ulink>.</para>
 <para><guilabel>Show HTML status bar</guilabel> activates a bar at the left side of the reader
 pane that tells you if a message is &html; or not. This is important because
 &html; messages might imitate the look of a signed and encrypted message, so
@@ -1919,7 +1919,7 @@
 	      <para>
 		Enter the address of the server for online validation
 		of certificates. The &URL;
-                is usually starting with <emphasis>http://</emphasis>.
+                is usually starting with <emphasis>https://</emphasis>.
 	      </para>
 	  </listitem>
 	</varlistentry>
diff --git a/doc/kmail2/faq.docbook b/doc/kmail2/faq.docbook
--- a/doc/kmail2/faq.docbook
+++ b/doc/kmail2/faq.docbook
@@ -27,7 +27,7 @@
       </para>
     </listitem>
   </itemizedlist>
-<para>You can also use the script in <ulink url="http://userbase.kde.org/Special:myLanguage/Tutorials/Modify_KDE_Software_Defaults">Tutorials/Modify_KDE_Software_Defaults</ulink></para>
+<para>You can also use the script in <ulink url="https://userbase.kde.org/Special:myLanguage/Tutorials/Modify_KDE_Software_Defaults">Tutorials/Modify_KDE_Software_Defaults</ulink></para>
 </answer>
 </qandaentry>
 
@@ -256,7 +256,7 @@
 <qandaentry>
   <question><para>Why does &kmail; not start up?</para></question>
 <answer>
-<para><emphasis>Symptom:</emphasis> You want to start &kmail; from a minimal desktop environment like <ulink url="http://en.wikipedia.org/wiki/Fvwm2">fvwm2</ulink>. It does not start.</para>
+<para><emphasis>Symptom:</emphasis> You want to start &kmail; from a minimal desktop environment like <ulink url="https://en.wikipedia.org/wiki/Fvwm2">fvwm2</ulink>. It does not start.</para>
 <para><emphasis>Reason:</emphasis> You are missing the <emphasis>dbus</emphasis> functionality.</para>
 <para><emphasis>Solution:</emphasis> Start &kmail; using dbus-launch like this:</para>
 <para><userinput>dbus-launch kmail</userinput></para>
@@ -557,7 +557,7 @@
 installation.</para>
 
 <para>If that is not the case, you may want to have a look at <ulink
-url="http://tldp.org/HOWTO/Mail-Queue.html">the Mail Queue
+url="https://www.tldp.org/HOWTO/Mail-Queue.html">the Mail Queue
 HOWTO</ulink>.</para></answer>
 </qandaentry>
 
diff --git a/doc/kmail2/intro.docbook b/doc/kmail2/intro.docbook
--- a/doc/kmail2/intro.docbook
+++ b/doc/kmail2/intro.docbook
@@ -85,7 +85,7 @@
 <title>Getting Help</title>
 <note><para>If you experience any problems migrating to &kmail; 2 please read the chapter <link linkend="troubleshooting">Troubleshooting</link>.
 </para></note>
-<para>&kmail;'s homepage can be found at <ulink url="http://userbase.kde.org/KMail">http://userbase.kde.org/KMail</ulink>. There you will
+<para>&kmail;'s homepage can be found at <ulink url="https://userbase.kde.org/KMail">https://userbase.kde.org/KMail</ulink>. There you will
 find useful links, &eg; to the user and developer mailing lists. Please report bugs in &kmail; using
 <menuchoice><guimenu>Help</guimenu><guimenuitem>Report Bug...</guimenuitem></menuchoice>.</para>
 </sect2>
diff --git a/doc/kmail2/troubleshooting.docbook b/doc/kmail2/troubleshooting.docbook
--- a/doc/kmail2/troubleshooting.docbook
+++ b/doc/kmail2/troubleshooting.docbook
@@ -4,7 +4,7 @@
 <authorgroup>
 <author>
 <personname>
-      <firstname>This chapter was converted from the KDE UserBase <ulink url="http://userbase.kde.org/KMail/FAQs Hints and Tips">KMail/FAQs Hints and Tips</ulink> page.</firstname>
+      <firstname>This chapter was converted from the KDE UserBase <ulink url="https://userbase.kde.org/KMail/FAQs Hints and Tips">KMail/FAQs Hints and Tips</ulink> page.</firstname>
 <surname></surname>
 </personname>
       </author>
diff --git a/doc/kmail2/using-kmail.docbook b/doc/kmail2/using-kmail.docbook
--- a/doc/kmail2/using-kmail.docbook
+++ b/doc/kmail2/using-kmail.docbook
@@ -1875,7 +1875,7 @@
 properly; of course, we cannot give you a full introduction of
 <application>GnuPG</application> here. We will only mention the steps you have to
 do to get <application>GnuPG</application> going. For details you should have a look at 
-the <ulink url="http://www.gnupg.org/docs.html#guides">The &GNU; Privacy Handbook</ulink>.</para>
+the <ulink url="https://www.gnupg.org/docs.html#guides">The &GNU; Privacy Handbook</ulink>.</para>
 
 <para>It is certainly a good idea to study this documentation as well as an
 introduction into public key cryptography: there you can learn a lot about
diff --git a/ktnef/COPYING.DOC b/ktnef/COPYING.DOC
--- a/ktnef/COPYING.DOC
+++ b/ktnef/COPYING.DOC
@@ -355,7 +355,7 @@
 of the GNU Free Documentation License from time to time.  Such new
 versions will be similar in spirit to the present version, but may
 differ in detail to address new problems or concerns.  See
-http://www.gnu.org/copyleft/.
+https://www.gnu.org/copyleft/.
 
 Each version of the License is given a distinguishing version number.
 If the Document specifies that a particular numbered version of this
diff --git a/ktnef/doc/index.docbook b/ktnef/doc/index.docbook
--- a/ktnef/doc/index.docbook
+++ b/ktnef/doc/index.docbook
@@ -36,7 +36,7 @@
 <date>2016-07-27</date>
 <releaseinfo>5.3.40 (Applications 16.08)</releaseinfo>
 
-<abstract><para>The TNEF File Viewer is an application for <ulink url="http://en.wikipedia.org/wiki/TNEF">TNEF</ulink> mail attachments.</para></abstract>
+<abstract><para>The TNEF File Viewer is an application for <ulink url="https://en.wikipedia.org/wiki/TNEF">TNEF</ulink> mail attachments.</para></abstract>
 
 <keywordset>
 <keyword>mail</keyword>