diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.5)
-set(PIM_VERSION "5.11.40")
+set(PIM_VERSION "5.11.41")
 
 project(KIMAP VERSION ${PIM_VERSION})
 
diff --git a/src/session.h b/src/session.h
--- a/src/session.h
+++ b/src/session.h
@@ -91,6 +91,18 @@
      */
     Q_REQUIRED_RESULT QString selectedMailBox() const;
 
+   /**
+    * Sets whether the IMAP network connection should use the system proxy settings.
+    *
+    * @param useProxy @c true if the proxy is to be used
+    * The default is to not use the proxy.
+    * @since 5.11.41
+    *
+    * @note If the session is currently connected to the IMAP server, calling this
+    * function will disconnect and reconnect to it with the changed proxy setting.
+    */
+    void setUseNetworkProxy(bool useProxy);
+
     Q_REQUIRED_RESULT int jobQueueSize() const;
 
     void close();
diff --git a/src/session.cpp b/src/session.cpp
--- a/src/session.cpp
+++ b/src/session.cpp
@@ -98,6 +98,11 @@
     return d->thread->port();
 }
 
+void Session::setUseNetworkProxy(bool useProxy)
+{
+    d->thread->setUseNetworkProxy(useProxy);
+}
+
 Session::State Session::state() const
 {
     return d->state;
diff --git a/src/sessionthread.cpp b/src/sessionthread.cpp
--- a/src/sessionthread.cpp
+++ b/src/sessionthread.cpp
@@ -21,6 +21,7 @@
 
 #include <QDebug>
 #include <QThread>
+#include <QNetworkProxy>
 
 #include "kimap_debug.h"
 
@@ -37,7 +38,8 @@
 SessionThread::SessionThread(const QString &hostName, quint16 port)
     : QObject(), m_hostName(hostName), m_port(port),
       m_socket(nullptr), m_stream(nullptr), m_mutex(),
-      m_encryptedMode(false)
+      m_encryptedMode(false),
+      m_useProxy(false)
 {
     // Just like the Qt docs now recommend, for event-driven threads:
     // don't derive from QThread, create one directly and move the object to it.
@@ -59,6 +61,12 @@
     delete thread();
 }
 
+// Called in primary thread, passes setting to secondary thread
+void SessionThread::setUseNetworkProxy(bool useProxy)
+{
+    QMetaObject::invokeMethod(this, [this, useProxy]() { setUseProxyInternal(useProxy); }, Qt::QueuedConnection);
+}
+
 // Called in primary thread
 void SessionThread::sendData(const QByteArray &payload)
 {
@@ -162,6 +170,17 @@
     }
     if (m_socket->state() != SessionSocket::ConnectedState &&
             m_socket->state() != SessionSocket::ConnectingState) {
+
+        QNetworkProxy proxy;
+        if (!m_useProxy) {
+            qCDebug(KIMAP_LOG) << "Connecting to IMAP server with no proxy";
+            proxy.setType(QNetworkProxy::NoProxy);
+        } else {
+            qCDebug(KIMAP_LOG) << "Connecting to IMAP server using default system proxy";
+            proxy.setType(QNetworkProxy::DefaultProxy);
+        }
+        m_socket->setProxy(proxy);
+
         if (m_encryptedMode) {
             qCDebug(KIMAP_LOG) << "connectToHostEncrypted" << m_hostName << m_port;
             m_socket->connectToHostEncrypted(m_hostName, m_port);
@@ -210,6 +229,18 @@
     thread()->quit();
 }
 
+// Called in secondary thread
+void SessionThread::setUseProxyInternal(bool useProxy)
+{
+    m_useProxy = useProxy;
+    if (m_socket != nullptr) {
+        if (m_socket->state() != SessionSocket::UnconnectedState) {
+            m_socket->disconnectFromHost();
+            QMetaObject::invokeMethod(this, &SessionThread::reconnect, Qt::QueuedConnection);
+        }
+    }
+}
+
 // Called in primary thread
 void SessionThread::startSsl(KTcpSocket::SslVersion version)
 {
diff --git a/src/sessionthread_p.h b/src/sessionthread_p.h
--- a/src/sessionthread_p.h
+++ b/src/sessionthread_p.h
@@ -50,6 +50,8 @@
         return m_port;
     }
 
+    void setUseNetworkProxy(bool useProxy);
+
     void sendData(const QByteArray &payload);
 
 public Q_SLOTS:
@@ -78,6 +80,7 @@
     void slotSocketDisconnected();
     void doStartSsl(KTcpSocket::SslVersion);
     void doSslErrorHandlerResponse(bool result);
+    void setUseProxyInternal(bool useProxy);
 
 private:
     QString m_hostName;
@@ -92,6 +95,7 @@
     QMutex m_mutex;
 
     bool m_encryptedMode = false;
+    bool m_useProxy = false;
 };
 
 }