diff --git a/src/librssguard/gui/messagepreviewer.cpp b/src/librssguard/gui/messagepreviewer.cpp
index cc9fbcc1f..02516b97f 100755
--- a/src/librssguard/gui/messagepreviewer.cpp
+++ b/src/librssguard/gui/messagepreviewer.cpp
@@ -47,7 +47,7 @@ void MessagePreviewer::createConnections() {
 
 MessagePreviewer::MessagePreviewer(QWidget* parent)
   : QWidget(parent), m_layout(new QGridLayout(this)), m_toolBar(new QToolBar(this)), m_verticalScrollBarPosition(0.0),
-  m_separator(nullptr), m_btnLabels(QList<QPair<QToolButton*, QAction*>>()) {
+  m_separator(nullptr), m_btnLabels(QList<QPair<LabelButton*, QAction*>>()) {
 #if defined (USE_WEBENGINE)
   m_txtMessage = new WebBrowser(this);
 #else
@@ -115,6 +115,21 @@ void MessagePreviewer::loadMessage(const Message& message, RootItem* root) {
   }
 }
 
+void MessagePreviewer::switchLabel(bool assign) {
+  auto lbl = qobject_cast<LabelButton*>(sender())->label();
+
+  if (lbl == nullptr) {
+    return;
+  }
+
+  if (assign) {
+    lbl->assignToMessage(m_message);
+  }
+  else {
+    lbl->deassignFromMessage(m_message);
+  }
+}
+
 void MessagePreviewer::markMessageAsRead() {
   markMessageAsReadUnread(RootItem::ReadStatus::Read);
 }
@@ -192,23 +207,34 @@ void MessagePreviewer::updateLabels(bool only_clear) {
 
   if (m_root.data() != nullptr) {
     m_separator = m_toolBar->addSeparator();
+    QSqlDatabase database = qApp->database()->connection(metaObject()->className());
 
     for (auto* label : m_root.data()->getParentServiceRoot()->labelsNode()->labels()) {
-      QToolButton* btn_label = new QToolButton(this);
+      LabelButton* btn_label = new LabelButton(this);
 
+      btn_label->setLabel(label);
       btn_label->setCheckable(true);
       btn_label->setIcon(Label::generateIcon(label->color()));
       btn_label->setAutoRaise(false);
       btn_label->setText(label->title());
       btn_label->setToolButtonStyle(Qt::ToolButtonStyle::ToolButtonTextBesideIcon);
+      btn_label->setChecked(DatabaseQueries::isLabelAssignedToMessage(database, label, m_message));
 
       QAction* act_label = m_toolBar->addWidget(btn_label);
 
-      connect(act_label, &QAction::triggered, this, []() {
-        int a = 5;
-      });
+      connect(btn_label, &QToolButton::toggled, this, &MessagePreviewer::switchLabel);
 
-      m_btnLabels.append(QPair<QToolButton*, QAction*>(btn_label, act_label));
+      m_btnLabels.append({ btn_label, act_label });
     }
   }
 }
+
+LabelButton::LabelButton(QWidget* parent) : QToolButton(parent), m_label(nullptr) {}
+
+Label* LabelButton::label() const {
+  return m_label.data();
+}
+
+void LabelButton::setLabel(Label* label) {
+  m_label = label;
+}
diff --git a/src/librssguard/gui/messagepreviewer.h b/src/librssguard/gui/messagepreviewer.h
index 2856a706e..54a422300 100644
--- a/src/librssguard/gui/messagepreviewer.h
+++ b/src/librssguard/gui/messagepreviewer.h
@@ -3,14 +3,14 @@
 #ifndef MESSAGEPREVIEWER_H
 #define MESSAGEPREVIEWER_H
 
-#include <QWidget>
+#include <QToolButton>
 
 #include "core/message.h"
+#include "services/abstract/label.h"
 #include "services/abstract/rootitem.h"
 
 #include <QPointer>
 
-class QToolButton;
 class QGridLayout;
 class QToolBar;
 
@@ -20,6 +20,19 @@ class WebBrowser;
 class MessageBrowser;
 #endif
 
+class LabelButton : public QToolButton {
+  Q_OBJECT
+
+  public:
+    explicit LabelButton(QWidget* parent = nullptr);
+
+    Label* label() const;
+    void setLabel(Label* label);
+
+  private:
+    QPointer<Label> m_label;
+};
+
 class MessagePreviewer : public QWidget {
   Q_OBJECT
 
@@ -38,6 +51,7 @@ class MessagePreviewer : public QWidget {
     void loadMessage(const Message& message, RootItem* root);
 
   private slots:
+    void switchLabel(bool assign);
     void markMessageAsRead();
     void markMessageAsUnread();
     void markMessageAsReadUnread(RootItem::ReadStatus read);
@@ -70,7 +84,7 @@ class MessagePreviewer : public QWidget {
     QAction* m_actionMarkUnread;
     QAction* m_actionSwitchImportance;
     QAction* m_separator;
-    QList<QPair<QToolButton*, QAction*>> m_btnLabels;
+    QList<QPair<LabelButton*, QAction*>> m_btnLabels;
 };
 
 #endif // MESSAGEPREVIEWER_H
diff --git a/src/librssguard/gui/messagesview.cpp b/src/librssguard/gui/messagesview.cpp
index 8288ebeda..3c6910014 100644
--- a/src/librssguard/gui/messagesview.cpp
+++ b/src/librssguard/gui/messagesview.cpp
@@ -152,7 +152,7 @@ void MessagesView::setupAppearance() {
   header()->setDefaultSectionSize(MESSAGES_VIEW_DEFAULT_COL);
   header()->setMinimumSectionSize(MESSAGES_VIEW_MINIMUM_COL);
   header()->setCascadingSectionResizes(false);
-  header()->setStretchLastSection(false);
+  header()->setStretchLastSection(true);
 }
 
 void MessagesView::focusInEvent(QFocusEvent* event) {
diff --git a/src/librssguard/miscellaneous/databasequeries.cpp b/src/librssguard/miscellaneous/databasequeries.cpp
index 437b76849..87c756d47 100755
--- a/src/librssguard/miscellaneous/databasequeries.cpp
+++ b/src/librssguard/miscellaneous/databasequeries.cpp
@@ -31,6 +31,55 @@
 #include <QUrl>
 #include <QVariant>
 
+bool DatabaseQueries::isLabelAssignedToMessage(const QSqlDatabase& db, Label* label, const Message& msg) {
+  QSqlQuery q(db);
+
+  q.setForwardOnly(true);
+  q.prepare("SELECT COUNT(*) FROM LabelsInMessages WHERE label = :label AND message = :message AND account_id = :account_id;");
+  q.bindValue(QSL(":label"), label->customId());
+  q.bindValue(QSL(":message"), msg.m_customId);
+  q.bindValue(QSL(":account_id"), label->getParentServiceRoot()->accountId());
+
+  q.exec() && q.next();
+
+  return q.record().value(0).toInt() > 0;
+}
+
+bool DatabaseQueries::deassignLabelFromMessage(const QSqlDatabase& db, Label* label, const Message& msg) {
+  QSqlQuery q(db);
+
+  q.setForwardOnly(true);
+  q.prepare("DELETE FROM LabelsInMessages WHERE label = :label AND message = :message AND account_id = :account_id;");
+  q.bindValue(QSL(":label"), label->customId());
+  q.bindValue(QSL(":message"), msg.m_customId);
+  q.bindValue(QSL(":account_id"), label->getParentServiceRoot()->accountId());
+
+  return q.exec();
+}
+
+bool DatabaseQueries::assignLabelToMessage(const QSqlDatabase& db, Label* label, const Message& msg) {
+  QSqlQuery q(db);
+
+  q.setForwardOnly(true);
+  q.prepare("DELETE FROM LabelsInMessages WHERE label = :label AND message = :message AND account_id = :account_id;");
+  q.bindValue(QSL(":label"), label->customId());
+  q.bindValue(QSL(":message"), msg.m_customId);
+  q.bindValue(QSL(":account_id"), label->getParentServiceRoot()->accountId());
+
+  auto succ = q.exec();
+
+  if (succ) {
+    q.prepare("INSERT INTO LabelsInMessages (label, message, account_id) VALUES (:label, :message, :account_id);");
+    q.bindValue(QSL(":label"), label->customId());
+    q.bindValue(QSL(":message"), msg.m_customId);
+    q.bindValue(QSL(":account_id"), label->getParentServiceRoot()->accountId());
+
+    succ = q.exec();
+  }
+
+  return succ;
+}
+
 QList<Label*> DatabaseQueries::getLabels(const QSqlDatabase& db, int account_id) {
   QList<Label*> labels;
   QSqlQuery q(db);
@@ -104,6 +153,10 @@ bool DatabaseQueries::createLabel(const QSqlDatabase& db, Label* label, int acco
 
   if (res && q.lastInsertId().isValid()) {
     label->setId(q.lastInsertId().toInt());
+
+    // NOTE: This custom ID in this object will be probably
+    // overwritten in online-synchronized labels.
+    label->setCustomId(QString::number(label->id()));
   }
 
   // Fixup missing custom IDs.
diff --git a/src/librssguard/miscellaneous/databasequeries.h b/src/librssguard/miscellaneous/databasequeries.h
index 134c3cfe1..48fe15796 100644
--- a/src/librssguard/miscellaneous/databasequeries.h
+++ b/src/librssguard/miscellaneous/databasequeries.h
@@ -19,6 +19,9 @@ class DatabaseQueries {
   public:
 
     // Label operators.
+    static bool isLabelAssignedToMessage(const QSqlDatabase& db, Label* label, const Message& msg);
+    static bool deassignLabelFromMessage(const QSqlDatabase& db, Label* label, const Message& msg);
+    static bool assignLabelToMessage(const QSqlDatabase& db, Label* label, const Message& msg);
     static QList<Label*> getLabels(const QSqlDatabase& db, int account_id);
     static bool updateLabel(const QSqlDatabase& db, Label* label);
     static bool deleteLabel(const QSqlDatabase& db, Label* label);
diff --git a/src/librssguard/services/abstract/label.cpp b/src/librssguard/services/abstract/label.cpp
index 8355a2ca5..b375a7499 100755
--- a/src/librssguard/services/abstract/label.cpp
+++ b/src/librssguard/services/abstract/label.cpp
@@ -95,6 +95,24 @@ QIcon Label::generateIcon(const QColor& color) {
   return pxm;
 }
 
+void Label::assignToMessage(const Message& msg) {
+  QSqlDatabase database = qApp->database()->connection(metaObject()->className());
+
+  DatabaseQueries::assignLabelToMessage(database, this, msg);
+
+  updateCounts(true);
+  getParentServiceRoot()->itemChanged({ this });
+}
+
+void Label::deassignFromMessage(const Message& msg) {
+  QSqlDatabase database = qApp->database()->connection(metaObject()->className());
+
+  DatabaseQueries::deassignLabelFromMessage(database, this, msg);
+
+  updateCounts(true);
+  getParentServiceRoot()->itemChanged({ this });
+}
+
 void Label::setCountOfAllMessages(int totalCount) {
   m_totalCount = totalCount;
 }
diff --git a/src/librssguard/services/abstract/label.h b/src/librssguard/services/abstract/label.h
index 3f25bce23..182089b76 100755
--- a/src/librssguard/services/abstract/label.h
+++ b/src/librssguard/services/abstract/label.h
@@ -29,6 +29,10 @@ class Label : public RootItem {
     virtual void updateCounts(bool including_total_count);
     static QIcon generateIcon(const QColor& color);
 
+  public slots:
+    void assignToMessage(const Message& msg);
+    void deassignFromMessage(const Message& msg);
+
   private:
     QColor m_color;
     int m_totalCount{};