diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCQtProxy.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCQtProxy.cpp
index b052e76e..0e466b7b 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCQtProxy.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCQtProxy.cpp
@@ -44,9 +44,7 @@ void GRPCQtProxy::connectSignals()
     connect(this, &GRPCQtProxy::reportBugReceived, &settingsTab, &SettingsTab::setBugReport);
     connect(this, &GRPCQtProxy::setIsStreamingReceived, &settingsTab, &SettingsTab::setIsStreaming);
     connect(this, &GRPCQtProxy::setClientPlatformReceived, &settingsTab, &SettingsTab::setClientPlatform);
-    connect(this, &GRPCQtProxy::changePortsReceived, &settingsTab, &SettingsTab::changePorts);
-    connect(this, &GRPCQtProxy::setUseSSLForIMAPReceived, &settingsTab, &SettingsTab::setUseSSLForIMAP);
-    connect(this, &GRPCQtProxy::setUseSSLForSMTPReceived, &settingsTab, &SettingsTab::setUseSSLForSMTP);
+    connect(this, &GRPCQtProxy::setMailServerSettingsReceived, &settingsTab, &SettingsTab::setMailServerSettings);
     connect(this, &GRPCQtProxy::setIsDoHEnabledReceived, &settingsTab, &SettingsTab::setIsDoHEnabled);
     connect(this, &GRPCQtProxy::setDiskCachePathReceived, &settingsTab, &SettingsTab::setDiskCachePath);
     connect(this, &GRPCQtProxy::setIsAutomaticUpdateOnReceived, &settingsTab, &SettingsTab::setIsAutomaticUpdateOn);
@@ -137,30 +135,14 @@ void GRPCQtProxy::setClientPlatform(QString const &clientPlatform)
 
 
 //****************************************************************************************************************************************************
-/// \param[in] imapPort The IMAP port
-/// \param[in] smtpPort The SMTP port
+/// \param[in] imapPort The IMAP port.
+/// \param[in] smtpPort The SMTP port.
+/// \param[in] useSSLForIMAP The IMAP connexion mode.
+/// \param[in] useSSLForSMTP The IMAP connexion mode.
 //****************************************************************************************************************************************************
-void GRPCQtProxy::changePorts(qint32 imapPort, qint32 smtpPort)
+void GRPCQtProxy::setMailServerSettings(qint32 imapPort, qint32 smtpPort, bool useSSLForIMAP, bool userSSLForSMTP)
 {
-    emit changePortsReceived(imapPort, smtpPort);
-}
-
-
-//****************************************************************************************************************************************************
-/// \param[in] use Should SMTP use SSL?
-//****************************************************************************************************************************************************
-void GRPCQtProxy::setUseSSLForIMAP(bool use)
-{
-    emit setUseSSLForIMAPReceived(use);
-}
-
-
-//****************************************************************************************************************************************************
-/// \param[in] use Should SMTP use SSL?
-//****************************************************************************************************************************************************
-void GRPCQtProxy::setUseSSLForSMTP(bool use)
-{
-    emit setUseSSLForSMTPReceived(use);
+    emit setMailServerSettingsReceived(imapPort, smtpPort, useSSLForIMAP, userSSLForSMTP);
 }
 
 
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCQtProxy.h b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCQtProxy.h
index 7aad0b8c..9609f0b6 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCQtProxy.h
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCQtProxy.h
@@ -46,10 +46,8 @@ public: // member functions.
     void reportBug(QString const &osType, QString const &osVersion, QString const &emailClient, QString const &address,
         QString const &description, bool includeLogs); ///< Forwards a ReportBug call via a Qt signal.
     void setIsStreaming(bool isStreaming); ///< Forward a isStreaming internal messages via a Qt signal.
-    void setClientPlatform(QString const &clientPlatform); ///< Forward s setClientPlatform call via a Qt signal.
-    void changePorts(qint32 imapPort, qint32 smtpPort); ///< Forwards a ChangePorts call via a Qt signal.
-    void setUseSSLForIMAP(bool use); ///< Forwards a SetUseSSLForIMAP call via a Qt signal.
-    void setUseSSLForSMTP(bool use); ///< Forwards a SetUseSSLForSMTP call via a Qt signal.
+    void setClientPlatform(QString const &clientPlatform); ///< Forward a setClientPlatform call via a Qt signal.
+    void setMailServerSettings(qint32 imapPort, qint32 smtpPort, bool useSSLForIMAP, bool userSSLForSMTP); ///< Forwards a setMailServerSettings' call via a Qt signal.
     void setIsDoHEnabled(bool enabled); ///< Forwards a setIsDoHEnabled call via a Qt signal.
     void setDiskCachePath(QString const &path); ///< Forwards a setDiskCachePath call via a Qt signal.
     void setIsAutomaticUpdateOn(bool on); ///< Forwards a SetIsAutomaticUpdateOn call via a Qt signal.
@@ -68,9 +66,7 @@ signals:
         QString const &description, bool includeLogs); ///< Signal for the ReportBug gRPC call
     void setIsStreamingReceived(bool isStreaming); ///< Signal for the IsStreaming internal message.
     void setClientPlatformReceived(QString const &clientPlatform); ///< Signal for the SetClientPlatform gRPC call.
-    void changePortsReceived(qint32 imapPort, qint32 smtpPort); ///< Signal for the ChangePorts gRPC call.
-    void setUseSSLForIMAPReceived(bool use); ///< Signal for the SetUseSSLForIMAP gRPC call.
-    void setUseSSLForSMTPReceived(bool use); ///< Signal for the SetUseSSLForSMTP gRPC call.
+    void setMailServerSettingsReceived(qint32 imapPort, qint32 smtpPort, bool useSSLForIMAP, bool userSSLForSMTP); ///< Signal for the SetMailServerSettings gRPC call.
     void setIsDoHEnabledReceived(bool enabled); ///< Signal for the SetIsDoHEnabled gRPC call.
     void setDiskCachePathReceived(QString const &path); ///< Signal for the setDiskCachePath gRPC call.
     void setIsAutomaticUpdateOnReceived(bool on); ///< Signal for the SetIsAutomaticUpdateOn gRPC call.
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCServerWorker.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCServerWorker.cpp
index fb7af161..e2b1a6e3 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCServerWorker.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCServerWorker.cpp
@@ -62,7 +62,17 @@ void GRPCServerWorker::run()
         credentials->SetAuthMetadataProcessor(processor_); // gRPC interceptors are still experimental in C++, so we use AuthMetadataProcessor
         ServerBuilder builder;
         int port = 0; // Port will not be known until ServerBuilder::BuildAndStart() is called
-        builder.AddListeningPort("127.0.0.1:0", credentials, &port);
+        bool const useFileSocket = useFileSocketForGRPC();
+        if (useFileSocket) {
+            QString const fileSocketPath = getAvailableFileSocketPath();
+            if (fileSocketPath.isEmpty())
+                throw Exception("Could not get an available file socket.");
+            builder.AddListeningPort(QString("unix://%1").arg(fileSocketPath).toStdString(), credentials);
+            config.fileSocketPath = fileSocketPath;
+        } else {
+            builder.AddListeningPort("127.0.0.1:0", credentials, &port);
+        }
+
         builder.RegisterService(&app().grpc());
         server_ = builder.BuildAndStart();
 
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCService.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCService.cpp
index d2dad963..785e91f5 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCService.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCService.cpp
@@ -635,51 +635,31 @@ Status GRPCService::IsDoHEnabled(ServerContext *, Empty const *, BoolValue *resp
 
 
 //****************************************************************************************************************************************************
-/// \param[in] request The request.
+/// \param[in] settings The IMAP/SMTP settings.
 /// \return The status for the call.
 //****************************************************************************************************************************************************
-Status GRPCService::SetUseSslForImap(ServerContext *, BoolValue const *request, Empty *)
+Status GRPCService::SetMailServerSettings(::grpc::ServerContext *context, ImapSmtpSettings const *settings, Empty *)
 {
     app().log().debug(__FUNCTION__);
-    qtProxy_.setUseSSLForIMAP(request->value());
-    qtProxy_.sendDelayedEvent(newUseSslForImapFinishedEvent());
+    qtProxy_.setMailServerSettings(settings->imapport(), settings->smtpport(), settings->usesslforimap(), settings->usesslforsmtp());
+    qtProxy_.sendDelayedEvent(newMailServerSettingsChanged(*settings));
+    qtProxy_.sendDelayedEvent(newChangeMailServerSettingsFinished());
     return Status::OK;
 }
 
 
 //****************************************************************************************************************************************************
-/// \param[out] response The response.
+/// \param[out] outSettings The settings
 /// \return The status for the call.
 //****************************************************************************************************************************************************
-Status GRPCService::UseSslForImap(ServerContext *, Empty const *, BoolValue *response)
+Status GRPCService::MailServerSettings(::grpc::ServerContext *, Empty const *, ImapSmtpSettings *outSettings)
 {
     app().log().debug(__FUNCTION__);
-    response->set_value(app().mainWindow().settingsTab().useSSLForIMAP());
-    return Status::OK;
-}
-
-
-//****************************************************************************************************************************************************
-/// \param[in] request The request.
-/// \return The status for the call.
-//****************************************************************************************************************************************************
-Status GRPCService::SetUseSslForSmtp(ServerContext *, BoolValue const *request, Empty *)
-{
-    app().log().debug(__FUNCTION__);
-    qtProxy_.setUseSSLForSMTP(request->value());
-    qtProxy_.sendDelayedEvent(newUseSslForSmtpFinishedEvent());
-    return Status::OK;
-}
-
-
-//****************************************************************************************************************************************************
-/// \param[out] response The response.
-/// \return The status for the call.
-//****************************************************************************************************************************************************
-Status GRPCService::UseSslForSmtp(ServerContext *, Empty const *, BoolValue *response)
-{
-    app().log().debug(__FUNCTION__);
-    response->set_value(app().mainWindow().settingsTab().useSSLForSMTP());
+    SettingsTab& tab = app().mainWindow().settingsTab();
+    outSettings->set_imapport(tab.imapPort());
+    outSettings->set_smtpport(tab.smtpPort());
+    outSettings->set_usesslforimap(tab.useSSLForIMAP());
+    outSettings->set_usesslforimap(tab.useSSLForSMTP());
     return Status::OK;
 }
 
@@ -696,43 +676,6 @@ Status GRPCService::Hostname(ServerContext *, Empty const *, StringValue *respon
 }
 
 
-//****************************************************************************************************************************************************
-/// \param[out] response The response.
-/// \return The status for the call.
-//****************************************************************************************************************************************************
-Status GRPCService::ImapPort(ServerContext *, Empty const *, Int32Value *response)
-{
-    app().log().debug(__FUNCTION__);
-    response->set_value(app().mainWindow().settingsTab().imapPort());
-    return Status::OK;
-}
-
-
-//****************************************************************************************************************************************************
-/// \param[out] response The response.
-/// \return The status for the call.
-//****************************************************************************************************************************************************
-Status GRPCService::SmtpPort(ServerContext *, Empty const *, Int32Value *response)
-{
-    app().log().debug(__FUNCTION__);
-    response->set_value(app().mainWindow().settingsTab().smtpPort());
-    return Status::OK;
-}
-
-
-//****************************************************************************************************************************************************
-/// \param[in] request The request.
-/// \return The status for the call.
-//****************************************************************************************************************************************************
-Status GRPCService::ChangePorts(ServerContext *, ChangePortsRequest const *request, Empty *)
-{
-    app().log().debug(__FUNCTION__);
-    qtProxy_.changePorts(request->imapport(), request->smtpport());
-    qtProxy_.sendDelayedEvent(newChangePortsFinishedEvent());
-    return Status::OK;
-}
-
-
 //****************************************************************************************************************************************************
 /// \param[in] request The request.
 /// \param[out] response The response.
@@ -947,5 +890,3 @@ bool GRPCService::sendEvent(SPStreamEvent const &event)
         eventQueue_.push_back(event);
     return isStreaming_;
 }
-
-
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCService.h b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCService.h
index 64f1d5b4..fd72954d 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCService.h
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCService.h
@@ -80,14 +80,9 @@ public: // member functions.
     grpc::Status SetDiskCachePath(::grpc::ServerContext *, ::google::protobuf::StringValue const*, ::google::protobuf::Empty *r) override;
     grpc::Status SetIsDoHEnabled(::grpc::ServerContext *, ::google::protobuf::BoolValue const *request, ::google::protobuf::Empty *) override;
     grpc::Status IsDoHEnabled(::grpc::ServerContext *, ::google::protobuf::Empty const*, ::google::protobuf::BoolValue *response) override;
-    grpc::Status SetUseSslForSmtp(::grpc::ServerContext *, ::google::protobuf::BoolValue const *request, ::google::protobuf::Empty *) override;
-    grpc::Status UseSslForSmtp(::grpc::ServerContext *, ::google::protobuf::Empty const*, ::google::protobuf::BoolValue *response) override;
-    grpc::Status SetUseSslForImap(::grpc::ServerContext *, ::google::protobuf::BoolValue const *request, ::google::protobuf::Empty *) override;
-    grpc::Status UseSslForImap(::grpc::ServerContext *, ::google::protobuf::Empty const*, ::google::protobuf::BoolValue *response) override;
+    grpc::Status SetMailServerSettings(::grpc::ServerContext *context, ::grpc::ImapSmtpSettings const *request, ::google::protobuf::Empty *response) override;
+    grpc::Status MailServerSettings(::grpc::ServerContext *context, ::google::protobuf::Empty const *request, ::grpc::ImapSmtpSettings *response) override;
     grpc::Status Hostname(::grpc::ServerContext *, ::google::protobuf::Empty const*, ::google::protobuf::StringValue *response) override;
-    grpc::Status ImapPort(::grpc::ServerContext *, ::google::protobuf::Empty const*, ::google::protobuf::Int32Value *response) override;
-    grpc::Status SmtpPort(::grpc::ServerContext *, ::google::protobuf::Empty const*, ::google::protobuf::Int32Value *response) override;
-    grpc::Status ChangePorts(::grpc::ServerContext *, ::grpc::ChangePortsRequest const *request, ::google::protobuf::Empty *) override;
     grpc::Status IsPortFree(::grpc::ServerContext *, ::google::protobuf::Int32Value const *request, ::google::protobuf::BoolValue *response) override;
     grpc::Status AvailableKeychains(::grpc::ServerContext *, ::google::protobuf::Empty const*, ::grpc::AvailableKeychainsResponse *response) override;
     grpc::Status SetCurrentKeychain(::grpc::ServerContext *, ::google::protobuf::StringValue const *request, ::google::protobuf::Empty *) override;
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/MainWindow.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/MainWindow.cpp
index 606dd867..bf9b2eab 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/MainWindow.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/MainWindow.cpp
@@ -38,7 +38,7 @@ void addEntryToLogEdit(bridgepp::Log::Level level, const QString &message, QPlai
     QString log = logEdit.toPlainText().trimmed();
     if (!log.isEmpty())
         log += "\n";
-    logEdit.setPlainText(log + Log::logEntryToString(level, message));
+    logEdit.setPlainText(log + Log::logEntryToString(level, QDateTime::currentDateTime(), message));
 }
 
 
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/SettingsTab.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/SettingsTab.cpp
index a554a405..1ad14903 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/SettingsTab.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/SettingsTab.cpp
@@ -337,14 +337,17 @@ qint32 SettingsTab::smtpPort()
 //****************************************************************************************************************************************************
 /// \param[in] imapPort The IMAP port.
 /// \param[in] smtpPort The SMTP port.
+/// \param[in] useSSLForIMAP The IMAP connexion mode.
+/// \param[in] useSSLForSMTP The IMAP connexion mode.
 //****************************************************************************************************************************************************
-void SettingsTab::changePorts(qint32 imapPort, qint32 smtpPort)
+void SettingsTab::setMailServerSettings(qint32 imapPort, qint32 smtpPort, bool useSSLForIMAP, bool useSSLForSMTP)
 {
     ui_.spinPortIMAP->setValue(imapPort);
     ui_.spinPortSMTP->setValue(smtpPort);
+    ui_.checkUseSSLForIMAP->setChecked(useSSLForIMAP);
+    ui_.checkUseSSLForSMTP->setChecked(useSSLForSMTP);
 }
 
-
 //****************************************************************************************************************************************************
 /// \return The state of the 'Use SSL for SMTP' check box.
 //****************************************************************************************************************************************************
@@ -362,23 +365,6 @@ bool SettingsTab::useSSLForIMAP() const
 }
 
 
-//****************************************************************************************************************************************************
-/// \param[in] use The state of the 'Use SSL for SMTP' check box.
-//****************************************************************************************************************************************************
-void SettingsTab::setUseSSLForSMTP(bool use)
-{
-    ui_.checkUseSSLForSMTP->setChecked(use);
-}
-
-//****************************************************************************************************************************************************
-/// \param[in] use The state of the 'Use SSL for SMTP' check box.
-//****************************************************************************************************************************************************
-void SettingsTab::setUseSSLForIMAP(bool use)
-{
-    ui_.checkUseSSLForIMAP->setChecked(use);
-}
-
-
 //****************************************************************************************************************************************************
 /// \return The state of the the 'DoH enabled' check box.
 //****************************************************************************************************************************************************
@@ -524,4 +510,3 @@ void SettingsTab::resetUI()
 
     ui_.checkAutomaticUpdate->setChecked(true);
 }
-
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/SettingsTab.h b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/SettingsTab.h
index 47951d21..08d9a464 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/SettingsTab.h
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/SettingsTab.h
@@ -77,9 +77,7 @@ public slots:
     void setColorSchemeName(QString const &name); ///< Set the value for the 'Use Dark Theme' check box.
     void setBugReport(QString const &osType, QString const &osVersion, QString const &emailClient, QString const &address, QString const &description,
         bool includeLogs); ///< Set the content of the bug report box.
-    void changePorts(qint32 imapPort, qint32 smtpPort); ///< Change the IMAP and SMTP ports.
-    void setUseSSLForSMTP(bool use); ///< Set the value for the 'Use SSL for SMTP' check box.
-    void setUseSSLForIMAP(bool use); ///< Set the value for the 'Use SSL for IMAP' check box.
+    void setMailServerSettings(qint32 imapPort, qint32 smtpPort, bool useSSLForIMAP, bool useSSLForSMTP); ///< Change the mail server settings.
     void setIsDoHEnabled(bool enabled); ///< Set the value for the 'DoH Enabled' check box.
     void setDiskCachePath(QString const &path); ///< Set the value for the 'Cache On Disk Enabled' check box.
     void setIsAutomaticUpdateOn(bool on); ///< Set the value for the 'Automatic Update' check box.
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/UsersTab.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/UsersTab.cpp
index b7e2bbfd..1570b164 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/UsersTab.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/UsersTab.cpp
@@ -295,7 +295,7 @@ void UsersTab::logoutUser(QString const &userID)
         app().log().error(QString("%1 failed. unknown user %1").arg(__FUNCTION__, userID));
         return;
     }
-    user->setLoggedIn(false);
+    user->setState(UserState::SignedOut);
     users_.touch(index);
     app().mainWindow().sendDelayedEvent(newUserChangedEvent(userID));
 }
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/UserDialog.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/UserDialog.cpp
index 1003aedf..d20901e0 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/UserDialog.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/UserDialog.cpp
@@ -19,6 +19,9 @@
 #include "UserDialog.h"
 
 
+using namespace bridgepp;
+
+
 //****************************************************************************************************************************************************
 /// \param[in] user The user.
 /// \param[in] parent The parent widget of the dialog.
@@ -37,7 +40,7 @@ UserDialog::UserDialog(bridgepp::SPUser &user, QWidget *parent)
     ui_.editPassword->setText(user->password());
     ui_.editAddresses->setPlainText(user->addresses().join("\n"));
     ui_.editAvatarText->setText(user_->avatarText());
-    ui_.checkLoggedIn->setChecked(user_->loggedIn());
+    ui_.checkLoggedIn->setChecked(user_->state() == UserState::Connected);
     ui_.checkSplitMode->setChecked(user_->splitMode());
     ui_.checkSetupGuideSeen->setChecked(user_->setupGuideSeen());
     ui_.spinUsedBytes->setValue(user->usedBytes());
@@ -55,7 +58,7 @@ void UserDialog::onOK()
     user_->setPassword(ui_.editPassword->text());
     user_->setAddresses(ui_.editAddresses->toPlainText().split(QRegularExpression(R"(\s+)"), Qt::SkipEmptyParts));
     user_->setAvatarText(ui_.editAvatarText->text());
-    user_->setLoggedIn(ui_.checkLoggedIn->isChecked());
+    user_->setState(ui_.checkLoggedIn->isChecked() ? UserState::Connected: UserState::SignedOut);
     user_->setSplitMode(ui_.checkSplitMode->isChecked());
     user_->setSetupGuideSeen(ui_.checkSetupGuideSeen->isChecked());
     user_->setUsedBytes(float(ui_.spinUsedBytes->value()));
diff --git a/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/EventFactory.cpp b/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/EventFactory.cpp
index e8bd5f21..813b83e6 100644
--- a/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/EventFactory.cpp
+++ b/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/EventFactory.cpp
@@ -420,8 +420,6 @@ SPStreamEvent newDiskCachePathChangeFinishedEvent()
     return wrapCacheEvent(cacheEvent);
 }
 
-SPStreamEvent newChangeMailServerSettingsFinished(); ///< Create a new ChangeMailServerSettingsFinished event.
-
 //****************************************************************************************************************************************************
 /// \param[in] errorType The error type.
 /// \return The event.
@@ -440,10 +438,10 @@ SPStreamEvent newMailServerSettingsErrorEvent(grpc::MailServerSettingsErrorType
 /// \param[in] settings The settings.
 /// \return The event.
 //****************************************************************************************************************************************************
-SPStreamEvent newMailServerSettingsChanged(grpc::ImapSmtpSettings *settings)
+SPStreamEvent newMailServerSettingsChanged(grpc::ImapSmtpSettings const &settings)
 {
     auto event = new grpc::MailServerSettingsChangedEvent;
-    event->set_allocated_settings(settings);
+    event->set_allocated_settings(new grpc::ImapSmtpSettings(settings));
     auto mailServerSettingsEvent = new grpc::MailServerSettingsEvent;
     mailServerSettingsEvent->set_allocated_mailserversettingschanged(event);
     return wrapMailServerSettingsEvent(mailServerSettingsEvent);
diff --git a/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/EventFactory.h b/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/EventFactory.h
index 4605affb..8a9fdae9 100644
--- a/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/EventFactory.h
+++ b/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/EventFactory.h
@@ -60,7 +60,7 @@ SPStreamEvent newDiskCachePathChangeFinishedEvent(); ///< Create a new DiskCache
 
 // Mail settings related events
 SPStreamEvent newMailServerSettingsErrorEvent(grpc::MailServerSettingsErrorType errorType); ///< Create a new MailSettingsErrorEvent event.
-SPStreamEvent newMailServerSettingsChanged(grpc::ImapSmtpSettings settings); ///< Create a new ConnectionModeChanged event.
+SPStreamEvent newMailServerSettingsChanged(grpc::ImapSmtpSettings const &settings); ///< Create a new ConnectionModeChanged event.
 SPStreamEvent newChangeMailServerSettingsFinished(); ///< Create a new ChangeMailServerSettingsFinished event.
 
 // keychain related events
diff --git a/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/GRPCClient.cpp b/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/GRPCClient.cpp
index debd767d..55e29ffb 100644
--- a/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/GRPCClient.cpp
+++ b/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/GRPCClient.cpp
@@ -40,14 +40,6 @@ qint64 const grpcConnectionWaitTimeoutMs = 60000; ///< Timeout for the connectio
 qint64 const grpcConnectionRetryDelayMs = 10000; ///< Retry delay for the gRPC connection in milliseconds.
 
 
-//****************************************************************************************************************************************************
-/// return true if gRPC connection should use file socket instead of TCP socket.
-//****************************************************************************************************************************************************
-bool useFileSocket() {
-    return !onWindows();
-}
-
-
 } // anonymous namespace
 
 
@@ -124,7 +116,7 @@ bool GRPCClient::connectToServer(GRPCConfig const &config, ProcessMonitor *serve
         serverToken_ = config.token.toStdString();
         QString address;
         grpc::ChannelArguments chanArgs;
-        if (useFileSocket())
+        if (useFileSocketForGRPC())
         {
             address = QString("unix://" + config.fileSocketPath);
             chanArgs.SetSslTargetNameOverride("127.0.0.1"); // for file socket, we skip name verification to avoid a confusion localhost/127.0.0.1
diff --git a/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/GRPCUtils.cpp b/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/GRPCUtils.cpp
index 805d793d..d127d172 100644
--- a/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/GRPCUtils.cpp
+++ b/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/GRPCUtils.cpp
@@ -69,6 +69,14 @@ QString serverKeyFilename()
 }
 
 
+} // anonymous namespace
+
+
+//****************************************************************************************************************************************************
+/// return true if gRPC connection should use file socket instead of TCP socket.
+//****************************************************************************************************************************************************
+bool useFileSocketForGRPC() {
+    return !onWindows();
 }
 
 
@@ -278,4 +286,22 @@ void userToGRPC(User const &user, grpc::User &outGRPCUser)
 }
 
 
+//****************************************************************************************************************************************************
+/// \return The path to a file that can be used for a gRPC file socket.
+/// \return A null string if no path could be found.
+//****************************************************************************************************************************************************
+QString getAvailableFileSocketPath()
+{
+    QDir const tempDir(QStandardPaths::writableLocation(QStandardPaths::TempLocation));
+    for (qint32 i = 0; i < 10000; i++) {
+        QString const path = tempDir.absoluteFilePath(QString("bridge_%1.sock").arg(qint32(i), 4, 10, QChar('0')));
+        QFile f(path);
+        if ((!f.exists()) || f.remove())
+            return path;
+    }
+
+    return QString();
+}
+
+
 } // namespace bridgepp
\ No newline at end of file
diff --git a/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/GRPCUtils.h b/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/GRPCUtils.h
index dc02b742..244caeb4 100644
--- a/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/GRPCUtils.h
+++ b/internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/GRPCUtils.h
@@ -46,6 +46,8 @@ grpc::UserState userStateToGRPC(UserState state); ///< Convert a bridgepp::UserS
 UserState userStateFromGRPC(grpc::UserState state);  ///< Convert a grpc::UserState to a bridgepp::UserState.
 void userToGRPC(User const &user, grpc::User &outGRPCUser); ///< Convert a bridgepp::User to a grpc::User.
 SPUser userFromGRPC(grpc::User const &grpcUser); ///< Create a bridgepp::User from a grpc::User.
+bool useFileSocketForGRPC(); ///< Check whether the Bridge gRPC service should use file sockets instead of TCP sockets.
+QString getAvailableFileSocketPath(); ///< Return the path of a new available socket, or a null string if none could be found.
 
 
 }