diff --git a/CMakeLists.txt b/CMakeLists.txt
index 541582243..bc17cfe1f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -75,7 +75,7 @@ set(LIBKSIEVE_LIB_VERSION_LIB "5.10.40")
 find_package(KF5WebEngineViewer ${MESSAGELIB_LIB_VERSION_LIB} CONFIG REQUIRED)
 
 find_package(KF5AkonadiSearch "5.10.40" CONFIG REQUIRED)
-set_package_properties(KF5AkonadiSearch PROPERTIES DESCRIPTION "The Akonadi Search libraries" URL "http://www.kde.org" TYPE REQUIRED PURPOSE "Provides search capabilities in KMail and Akonadi")
+set_package_properties(KF5AkonadiSearch PROPERTIES DESCRIPTION "The Akonadi Search libraries" URL "https://www.kde.org" TYPE REQUIRED PURPOSE "Provides search capabilities in KMail and Akonadi")
 
 set(GPGMEPP_LIB_VERSION "1.8.0")
 find_package(Gpgmepp ${GPGMEPP_LIB_VERSION} CONFIG REQUIRED)
diff --git a/src/aboutdata.cpp b/src/aboutdata.cpp
index 755560f2a..c66503264 100644
--- a/src/aboutdata.cpp
+++ b/src/aboutdata.cpp
@@ -313,7 +313,7 @@ static const about_data credits[] = {
     { "Thomas Moenicke", nullptr, "tm@php-qt.org", nullptr },
     { "Dirk M\303\274ller", nullptr, nullptr, nullptr }, // QUrl() fixes and qt_cast optimizations
     { "Torgny Nyblom", nullptr, "nyblom@kde.org", nullptr },
-    { "OpenUsability", I18N_NOOP("Usability tests and improvements"), nullptr, "http://www.openusability.org" },
+    { "OpenUsability", I18N_NOOP("Usability tests and improvements"), nullptr, "https://www.openusability.org" },
     { "Mario Teijeiro Otero", nullptr, nullptr, nullptr }, // various vendor annotations fixes
     { "Kevin Ottens", nullptr, "ervin@kde.org", nullptr },
     { "Simon Perreault", nullptr, nullptr, nullptr }, // make the composer remember its "Use Fixed Font" setting (bug 49481)
@@ -364,7 +364,7 @@ AboutData::AboutData()
                  KAboutLicense::GPL,
                  i18n("Copyright © 1997–2018, KMail authors"),
                  QString(),
-                 QStringLiteral("http://userbase.kde.org/KMail"))
+                 QStringLiteral("https://userbase.kde.org/KMail"))
 {
     using KMail::authors;
     using KMail::credits;
diff --git a/src/dialog/archivefolderdialog.cpp b/src/dialog/archivefolderdialog.cpp
index 86c39403a..88ad7802d 100644
--- a/src/dialog/archivefolderdialog.cpp
+++ b/src/dialog/archivefolderdialog.cpp
@@ -14,7 +14,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 #include "archivefolderdialog.h"
 
diff --git a/src/dialog/archivefolderdialog.h b/src/dialog/archivefolderdialog.h
index 15613e75d..34985952c 100644
--- a/src/dialog/archivefolderdialog.h
+++ b/src/dialog/archivefolderdialog.h
@@ -14,7 +14,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 #ifndef ARCHIVEFOLDERDIALOG_H
 #define ARCHIVEFOLDERDIALOG_H
diff --git a/src/foldershortcutactionmanager.cpp b/src/foldershortcutactionmanager.cpp
index b5db2ee00..38648b48f 100644
--- a/src/foldershortcutactionmanager.cpp
+++ b/src/foldershortcutactionmanager.cpp
@@ -14,7 +14,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 #include "foldershortcutactionmanager.h"
 
diff --git a/src/foldershortcutactionmanager.h b/src/foldershortcutactionmanager.h
index 5b4e4c29c..de535403d 100644
--- a/src/foldershortcutactionmanager.h
+++ b/src/foldershortcutactionmanager.h
@@ -14,7 +14,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 #ifndef FOLDERSHORTCUTACTIONMANAGER_H
 #define FOLDERSHORTCUTACTIONMANAGER_H
diff --git a/src/identity/identitydialog.cpp b/src/identity/identitydialog.cpp
index 9da30a2f2..eb905c0d1 100644
--- a/src/identity/identitydialog.cpp
+++ b/src/identity/identitydialog.cpp
@@ -394,7 +394,7 @@ IdentityDialog::IdentityDialog(QWidget *parent)
                "<p>You can leave this blank, but KMail will not be able "
                "to digitally sign emails using OpenPGP; "
                "normal mail functions will not be affected.</p>"
-               "<p>You can find out more about keys at <a>http://www.gnupg.org</a></p></qt>");
+               "<p>You can find out more about keys at <a>https://www.gnupg.org</a></p></qt>");
     label = new QLabel(i18n("OpenPGP signing key:"), tab);
     label->setBuddy(mPGPSigningKeyRequester);
     mPGPSigningKeyRequester->setWhatsThis(msg);
@@ -412,7 +412,7 @@ IdentityDialog::IdentityDialog(QWidget *parent)
                "<p>You can leave this blank, but KMail will not be able "
                "to encrypt copies of outgoing messages to you using OpenPGP; "
                "normal mail functions will not be affected.</p>"
-               "<p>You can find out more about keys at <a>http://www.gnupg.org</a></p></qt>");
+               "<p>You can find out more about keys at <a>https://www.gnupg.org</a></p></qt>");
     label = new QLabel(i18n("OpenPGP encryption key:"), tab);
     label->setBuddy(mPGPEncryptionKeyRequester);
     mPGPEncryptionKeyRequester->setWhatsThis(msg);
diff --git a/src/identity/xfaceconfigurator.cpp b/src/identity/xfaceconfigurator.cpp
index 058b1889b..498482ce2 100644
--- a/src/identity/xfaceconfigurator.cpp
+++ b/src/identity/xfaceconfigurator.cpp
@@ -165,8 +165,8 @@ XFaceConfigurator::XFaceConfigurator(QWidget *parent)
     mTextEdit->editor()->setWordWrapMode(QTextOption::WrapAnywhere);
     mTextEdit->editor()->setSearchSupport(false);
     QLabel *label2 = new QLabel(i18n("Examples are available at <a "
-                                     "href=\"http://ace.home.xs4all.nl/X-Faces/\">"
-                                     "http://ace.home.xs4all.nl/X-Faces/</a>."), page);
+                                     "href=\"https://ace.home.xs4all.nl/X-Faces/\">"
+                                     "https://ace.home.xs4all.nl/X-Faces/</a>."), page);
     label2->setOpenExternalLinks(true);
     label2->setTextInteractionFlags(Qt::TextBrowserInteraction);
 
diff --git a/src/tag/tagactionmanager.cpp b/src/tag/tagactionmanager.cpp
index 81a2fad52..cb930afb8 100644
--- a/src/tag/tagactionmanager.cpp
+++ b/src/tag/tagactionmanager.cpp
@@ -16,7 +16,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 #include "tagactionmanager.h"
 
diff --git a/src/tag/tagactionmanager.h b/src/tag/tagactionmanager.h
index 6d6fdbfb2..2ee5ff7da 100644
--- a/src/tag/tagactionmanager.h
+++ b/src/tag/tagactionmanager.h
@@ -16,7 +16,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 #ifndef TAGACTIONMANAGER_H
 #define TAGACTIONMANAGER_H