diff --git a/build/wino-mail.sqlite b/build/wino-mail.sqlite
new file mode 100644
index 0000000..37758a3
Binary files /dev/null and b/build/wino-mail.sqlite differ
diff --git a/src/core/authenticator.cpp b/src/core/authenticator.cpp
index f27e8ff..9b3419c 100644
--- a/src/core/authenticator.cpp
+++ b/src/core/authenticator.cpp
@@ -9,33 +9,43 @@ Authenticator::Authenticator(QObject *parent)
 
 void Authenticator::exchangeAuthorizationCode(const QString &code, const QString &redirectUri)
 {
-    Q_UNUSED(code);
-    Q_UNUSED(redirectUri);
-    qDebug() << "[Authenticator] exchangeAuthorizationCode called (base implementation)";
+    QUrl url(m_tokenEndpoint);
+    QNetworkRequest request = createTokenRequest(url);
+
+    QByteArray postData;
+    postData.append("grant_type=authorization_code");
+    postData.append("&code=" + code.toUtf8());
+    postData.append("&redirect_uri=" + redirectUri.toUtf8());
+    postData.append("&client_id=" + QString(m_clientId).toUtf8());
+    postData.append("&client_secret=" + QString(m_clientSecret).toUtf8());
+
+    QNetworkReply *reply = m_networkManager->post(request, postData);
+    connect(reply, &QNetworkReply::finished, this, [this, reply]() {
+        handleTokenResponse(reply->readAll(), m_email, providerName());
+        reply->deleteLater();
+    });
 }
 
 void Authenticator::handleTokenResponse(const QByteArray &data, const QString &email, const QString &providerType)
 {
     QJsonDocument doc = QJsonDocument::fromJson(data);
-    if (doc.isNull() || !doc.isObject()) {
-        emit authenticationFailed("Invalid token response");
+    if (!doc.isObject()) {
+        emit authenticationFailed("Invalid response from server");
         return;
     }
 
     QJsonObject obj = doc.object();
-    QString accessToken = obj["access_token"].toString();
-    QString refreshToken = obj["refresh_token"].toString();
-    int expiresIn = obj["expires_in"].toInt();
+    if (obj.contains("error")) {
+        emit authenticationFailed(obj["error"].toString() + ": " + obj["error_description"].toString());
+        return;
+    }
 
     Account account;
     account.setEmail(email);
-    account.setAccessToken(accessToken);
-    account.setRefreshToken(refreshToken);
-    account.setTokenExpires(QDateTime::currentDateTimeUtc().addSecs(expiresIn));
-
-    if (providerType == "gmail") account.setType(AccountType::Gmail);
-    else if (providerType == "outlook") account.setType(AccountType::Outlook);
-    else account.setType(AccountType::IMAP);
+    account.setProvider(providerType);
+    account.setAccessToken(obj["access_token"].toString());
+    account.setRefreshToken(obj["refresh_token"].toString());
+    account.setTokenExpires(QDateTime::currentDateTimeUtc().addSecs(obj["expires_in"].toInt()));
 
     emit authenticationCompleted(account);
 }
diff --git a/src/core/gmailauthenticator.cpp b/src/core/gmailauthenticator.cpp
index deb5a2d..75cbdc7 100644
--- a/src/core/gmailauthenticator.cpp
+++ b/src/core/gmailauthenticator.cpp
@@ -24,7 +24,7 @@ GmailAuthenticator::GmailAuthenticator(QObject *parent)
     connect(m_callbackServer, &OAuthCallbackServer::codeReceived,
             this, &GmailAuthenticator::onAuthCodeReceived);
     connect(m_callbackServer, &OAuthCallbackServer::errorOccurred,
-            this, [this](const QString &error) {
+            [this](const QString &error) {
         emit authenticationFailed("OAuth callback error: " + error);
     });
 }
@@ -66,19 +66,8 @@ void GmailAuthenticator::onAuthCodeReceived(const QString &code, const QString &
 
     m_authCode = code;
 
-    // Exchange the authorization code for tokens
-    QUrlQuery params;
-    params.addQueryItem("code", code);
-    params.addQueryItem("client_id", m_clientId);
-    params.addQueryItem("client_secret", m_clientSecret);
-    params.addQueryItem("redirect_uri", m_redirectUri);
-    params.addQueryItem("grant_type", "authorization_code");
-
-    QNetworkRequest request = createTokenRequest(QUrl(m_tokenEndpoint));
-    QNetworkReply *reply = m_networkManager->post(request, params.toString(QUrl::FullyEncoded).toUtf8());
-    connect(reply, &QNetworkReply::finished, this, [this, reply]() {
-        onTokenReply(reply);
-    });
+    // Exchange the authorization code for tokens using base class implementation
+    exchangeAuthorizationCode(code, m_redirectUri);
 }
 
 void GmailAuthenticator::refreshToken(const Account &account)
@@ -94,23 +83,9 @@ void GmailAuthenticator::refreshToken(const Account &account)
     QNetworkRequest request = createTokenRequest(QUrl(m_tokenEndpoint));
     QNetworkReply *reply = m_networkManager->post(request, params.toString(QUrl::FullyEncoded).toUtf8());
     connect(reply, &QNetworkReply::finished, this, [this, reply]() {
-        onTokenReply(reply);
+        handleTokenResponse(reply->readAll(), m_email, "gmail");
+        reply->deleteLater();
     });
 }
 
-void GmailAuthenticator::onTokenReply(QNetworkReply *reply)
-{
-    if (reply->error() == QNetworkReply::NoError) {
-        QByteArray data = reply->readAll();
-        handleTokenResponse(data, m_email, "gmail");
-    } else {
-        QByteArray responseData = reply->readAll();
-        qWarning() << "[GmailAuthenticator] Token request failed:"
-                    << reply->errorString()
-                    << "Response:" << QString::fromUtf8(responseData);
-        emit authenticationFailed("Gmail token request failed: " + reply->errorString());
-    }
-    reply->deleteLater();
-}
-
-#include "gmailauthenticator.moc"
\ No newline at end of file
+#include "gmailauthenticator.moc"
diff --git a/src/core/outlookauthenticator.cpp b/src/core/outlookauthenticator.cpp
index 56c9349..5394872 100644
--- a/src/core/outlookauthenticator.cpp
+++ b/src/core/outlookauthenticator.cpp
@@ -24,7 +24,7 @@ OutlookAuthenticator::OutlookAuthenticator(QObject *parent)
     connect(m_callbackServer, &OAuthCallbackServer::codeReceived,
             this, &OutlookAuthenticator::onAuthCodeReceived);
     connect(m_callbackServer, &OAuthCallbackServer::errorOccurred,
-            this, [this](const QString &error) {
+            [this](const QString &error) {
         emit authenticationFailed("OAuth callback error: " + error);
     });
 }
@@ -58,18 +58,7 @@ void OutlookAuthenticator::onAuthCodeReceived(const QString &code, const QString
 
     m_callbackServer->stop();
 
-    QUrlQuery params;
-    params.addQueryItem("code", code);
-    params.addQueryItem("client_id", m_clientId);
-    params.addQueryItem("client_secret", m_clientSecret);
-    params.addQueryItem("redirect_uri", m_redirectUri);
-    params.addQueryItem("grant_type", "authorization_code");
-
-    QNetworkRequest request = createTokenRequest(QUrl(m_tokenEndpoint));
-    QNetworkReply *reply = m_networkManager->post(request, params.toString(QUrl::FullyEncoded).toUtf8());
-    connect(reply, &QNetworkReply::finished, this, [this, reply]() {
-        onTokenReply(reply);
-    });
+    exchangeAuthorizationCode(code, m_redirectUri);
 }
 
 void OutlookAuthenticator::refreshToken(const Account &account)
@@ -86,23 +75,9 @@ void OutlookAuthenticator::refreshToken(const Account &account)
     QNetworkRequest request = createTokenRequest(QUrl(m_tokenEndpoint));
     QNetworkReply *reply = m_networkManager->post(request, params.toString(QUrl::FullyEncoded).toUtf8());
     connect(reply, &QNetworkReply::finished, this, [this, reply]() {
-        onTokenReply(reply);
+        handleTokenResponse(reply->readAll(), m_email, "outlook");
+        reply->deleteLater();
     });
 }
 
-void OutlookAuthenticator::onTokenReply(QNetworkReply *reply)
-{
-    if (reply->error() == QNetworkReply::NoError) {
-        QByteArray data = reply->readAll();
-        handleTokenResponse(data, m_email, "outlook");
-    } else {
-        QByteArray responseData = reply->readAll();
-        qWarning() << "[OutlookAuthenticator] Token request failed:"
-                    << reply->errorString()
-                    << "Response:" << QString::fromUtf8(responseData);
-        emit authenticationFailed("Outlook token request failed: " + reply->errorString());
-    }
-    reply->deleteLater();
-}
-
-#include "outlookauthenticator.moc"
\ No newline at end of file
+#include "outlookauthenticator.moc"
diff --git a/src/ui/maillistview.cpp b/src/ui/maillistview.cpp
index b57b101..c9dbc4b 100644
--- a/src/ui/maillistview.cpp
+++ b/src/ui/maillistview.cpp
@@ -59,6 +59,12 @@ void MailListView::setupUI() {
     m_tableView->setModel(m_proxyModel);
 
     connect(m_tableView, &QTableView::clicked, this, &MailListView::onRowSelected);
+    connect(m_tableView, &QTableView::doubleClicked, this, [this](const QModelIndex &index) {
+        if (!index.isValid()) return;
+        QModelIndex sourceIndex = m_proxyModel->mapToSource(index);
+        int mailId = sourceIndex.data(EmailListModel::IdRole).toInt();
+        emit emailOpenRequested(mailId);
+    });
 
     layout->addWidget(m_tableView);
 }
diff --git a/src/ui/maillistview.h b/src/ui/maillistview.h
index 815038f..9bf7b1f 100644
--- a/src/ui/maillistview.h
+++ b/src/ui/maillistview.h
@@ -21,6 +21,7 @@ public:
 
 signals:
     void emailSelected(int mailId);
+    void emailOpenRequested(int mailId);
     void composeRequested();
 
 private slots:
diff --git a/src/ui/mainmainwindow.cpp b/src/ui/mainmainwindow.cpp
index 23810f3..fa089c1 100644
--- a/src/ui/mainmainwindow.cpp
+++ b/src/ui/mainmainwindow.cpp
@@ -164,12 +164,21 @@ void MainMainWindow::setupMailPage() {
     m_mailListView = new MailListView();
     connect(m_mailListView, &MailListView::emailSelected, this, &MainMainWindow::onEmailSelected);
     connect(m_mailListView, &MailListView::composeRequested, this, &MainMainWindow::onComposeRequested);
+    connect(m_mailListView, &MailListView::emailOpenRequested, this, [this](int mailId) {
+        openMailInIndependentWindow(mailId);
+    });
     m_folderSplitter->addWidget(m_mailListView);
 
     // Reader
     m_emailViewer = new ReaderView();
     m_emailViewer->setMinimumWidth(350);
     connect(m_emailViewer, &ReaderView::replyRequested, this, &MainMainWindow::onReaderReplyRequested);
+    connect(m_emailViewer, &ReaderView::detachRequested, this, [this]() {
+        std::optional<MailItem> currentItem = MailItemDao::findById(m_emailModel->getCurrentMailId());
+        if (currentItem) {
+            openMailInIndependentWindow(currentItem->id());
+        }
+    });
     m_folderSplitter->addWidget(m_emailViewer);
 
     // Default sizes: folder 240, list 380, reader flex
@@ -248,6 +257,24 @@ void MainMainWindow::onNewMessage() {
     switchToPage(PageCompose);
 }
 
+void MainMainWindow::openMailInIndependentWindow(int mailId) {
+    std::optional<MailItem> item = MailItemDao::findById(mailId);
+    if (!item.has_value()) return;
+
+    QMainWindow *detachedWin = new QMainWindow();
+    detachedWin->setWindowTitle(QString("Mail - %1").arg(item->subject()));
+    
+    ReaderView *detachedReader = new ReaderView();
+    detachedReader->setMailItem(&item.value());
+    
+    detachedWin->setCentralWidget(detachedReader);
+    detachedWin->resize(800, 600);
+    detachedWin->setAttribute(Qt::WA_DeleteOnClose);
+    detachedWin->show();
+    
+    statusBar()->showMessage("Opened mail in independent window", 3000);
+}
+
 void MainMainWindow::createToolBar() {
     m_toolBar = addToolBar("Main Toolbar");
     m_toolBar->setMovable(false);
diff --git a/src/ui/mainmainwindow.h b/src/ui/mainmainwindow.h
index 72bdcf8..89ced9c 100644
--- a/src/ui/mainmainwindow.h
+++ b/src/ui/mainmainwindow.h
@@ -34,6 +34,7 @@ private slots:
     void onComposeRequested();
     void onReaderReplyRequested(const MailItem *item);
     void onNewMessage();
+    void openMailInIndependentWindow(int mailId);
 
 private:
     void setupUI();
diff --git a/src/ui/readerview.cpp b/src/ui/readerview.cpp
index 99a1636..656e922 100644
--- a/src/ui/readerview.cpp
+++ b/src/ui/readerview.cpp
@@ -40,9 +40,13 @@ void ReaderView::setupUI() {
     m_forwardButton = new QPushButton("Forward");
     m_deleteButton = new QPushButton("Delete");
     m_deleteButton->setStyleSheet("color: red;");
-
+    
+    QPushButton *m_detachButton = new QPushButton("独立 (Independent)");
+    m_detachButton->setToolTip("Open in separate window");
+    
     actionsLayout->addWidget(m_replyButton);
     actionsLayout->addWidget(m_forwardButton);
+    actionsLayout->addWidget(m_detachButton);
     actionsLayout->addStretch();
     actionsLayout->addWidget(m_deleteButton);
 
@@ -59,6 +63,8 @@ void ReaderView::setupUI() {
     connect(m_replyButton, &QPushButton::clicked, [this]() {
         if (m_bodyViewer->toPlainText().isEmpty()) return;
     });
+
+    connect(m_detachButton, &QPushButton::clicked, this, &ReaderView::detachRequested);
 }
 
 void ReaderView::setMailItem(const MailItem* item) {
diff --git a/src/ui/readerview.h b/src/ui/readerview.h
index 19eb03f..48749b9 100644
--- a/src/ui/readerview.h
+++ b/src/ui/readerview.h
@@ -21,6 +21,8 @@ signals:
     void replyRequested(const MailItem* item);
     void forwardRequested(const MailItem* item);
     void deleteRequested(const MailItem* item);
+    void detachRequested();
+
 
 private:
     void setupUI();