diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 1eeebf1..1e5d93a 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -7,7 +7,7 @@ on:
 jobs:
   releases-matrix:
     name: Release Go Binary
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     strategy:
       matrix:
         # build and publish in parallel: linux/386, linux/amd64, darwin/386, darwin/amd64
diff --git a/README.md b/README.md
index 86fee8d..3f87609 100644
--- a/README.md
+++ b/README.md
@@ -97,6 +97,7 @@ SMTP_PORT: the SMTP port
 SMTP_USERNAME: the SMTP username to authenticate
 SMTP_PASSWORD: the SMTP user password
 SMTP_AUTH_TYPE: the authentication type. Possible values: PLAIN, LOGIN, NONE
+SMTP_ENCRYPTION: the encryption method. Possible values: SSL, SSLTLS, TLS or STARTTLS (default)
 EMAIL_FROM_ADDRESS: the sender's email address
 EMAIL_FROM_NAME: the sender's name
 ```
diff --git a/handler/routes.go b/handler/routes.go
index 19512c1..dd6a94a 100644
--- a/handler/routes.go
+++ b/handler/routes.go
@@ -138,7 +138,15 @@ func GetClient(db store.IStore) echo.HandlerFunc {
 	return func(c echo.Context) error {
 
 		clientID := c.Param("id")
-		clientData, err := db.GetClientByID(clientID, true)
+		qrCodeIncludeFwMark := c.QueryParam("qrCodeIncludeFwMark")
+		qrCodeSettings := model.QRCodeSettings{
+			Enabled:       true,
+			IncludeDNS:    true,
+			IncludeFwMark: qrCodeIncludeFwMark == "true",
+			IncludeMTU:    true,
+		}
+
+		clientData, err := db.GetClientByID(clientID, qrCodeSettings)
 		if err != nil {
 			return c.JSON(http.StatusNotFound, jsonHTTPResponse{false, "Client not found"})
 		}
@@ -257,7 +265,13 @@ func EmailClient(db store.IStore, mailer emailer.Emailer, emailSubject, emailCon
 		c.Bind(&payload)
 		// TODO validate email
 
-		clientData, err := db.GetClientByID(payload.ID, true)
+		qrCodeSettings := model.QRCodeSettings{
+			Enabled:       true,
+			IncludeDNS:    true,
+			IncludeFwMark: true,
+			IncludeMTU:    true,
+		}
+		clientData, err := db.GetClientByID(payload.ID, qrCodeSettings)
 		if err != nil {
 			log.Errorf("Cannot generate client id %s config file for downloading: %v", payload.ID, err)
 			return c.JSON(http.StatusNotFound, jsonHTTPResponse{false, "Client not found"})
@@ -304,7 +318,7 @@ func UpdateClient(db store.IStore) echo.HandlerFunc {
 		c.Bind(&_client)
 
 		// validate client existence
-		clientData, err := db.GetClientByID(_client.ID, false)
+		clientData, err := db.GetClientByID(_client.ID, model.QRCodeSettings{Enabled: false})
 		if err != nil {
 			return c.JSON(http.StatusNotFound, jsonHTTPResponse{false, "Client not found"})
 		}
@@ -370,7 +384,7 @@ func SetClientStatus(db store.IStore) echo.HandlerFunc {
 		clientID := data["id"].(string)
 		status := data["status"].(bool)
 
-		clientdata, err := db.GetClientByID(clientID, false)
+		clientdata, err := db.GetClientByID(clientID, model.QRCodeSettings{Enabled: false})
 		if err != nil {
 			return c.JSON(http.StatusNotFound, jsonHTTPResponse{false, err.Error()})
 		}
@@ -395,7 +409,7 @@ func DownloadClient(db store.IStore) echo.HandlerFunc {
 			return c.JSON(http.StatusNotFound, jsonHTTPResponse{false, "Missing clientid parameter"})
 		}
 
-		clientData, err := db.GetClientByID(clientID, false)
+		clientData, err := db.GetClientByID(clientID, model.QRCodeSettings{Enabled: false})
 		if err != nil {
 			log.Errorf("Cannot generate client id %s config file for downloading: %v", clientID, err)
 			return c.JSON(http.StatusNotFound, jsonHTTPResponse{false, "Client not found"})
diff --git a/model/client.go b/model/client.go
index 9609265..b9e8141 100644
--- a/model/client.go
+++ b/model/client.go
@@ -28,3 +28,10 @@ type ClientData struct {
 	Client *Client
 	QRCode string
 }
+
+type QRCodeSettings struct {
+	Enabled       bool
+	IncludeDNS    bool
+	IncludeFwMark bool
+	IncludeMTU    bool
+}
diff --git a/store/jsondb/jsondb.go b/store/jsondb/jsondb.go
index 285bc19..b0d39f5 100644
--- a/store/jsondb/jsondb.go
+++ b/store/jsondb/jsondb.go
@@ -81,14 +81,18 @@ func (o *JsonDB) Init() error {
 
 	// global settings
 	if _, err := os.Stat(globalSettingPath); os.IsNotExist(err) {
-
-		publicInterface, err := util.GetPublicIP()
-		if err != nil {
-			return err
+		endpointAddress := util.LookupEnvOrString(util.EndpointAddressEnvVar, "")
+		if endpointAddress == "" {
+			// automatically find an external IP address
+			publicInterface, err := util.GetPublicIP()
+			if err != nil {
+				return err
+			}
+			endpointAddress = publicInterface.IPAddress
 		}
 
 		globalSetting := new(model.GlobalSetting)
-		globalSetting.EndpointAddress = util.LookupEnvOrString(util.EndpointAddressEnvVar, publicInterface.IPAddress)
+		globalSetting.EndpointAddress = endpointAddress
 		globalSetting.DNSServers = util.LookupEnvOrStrings(util.DNSEnvVar, []string{util.DefaultDNS})
 		globalSetting.MTU = util.LookupEnvOrInt(util.MTUEnvVar, util.DefaultMTU)
 		globalSetting.PersistentKeepalive = util.LookupEnvOrInt(util.PersistentKeepaliveEnvVar, util.DefaultPersistentKeepalive)
@@ -190,7 +194,7 @@ func (o *JsonDB) GetClients(hasQRCode bool) ([]model.ClientData, error) {
 	return clients, nil
 }
 
-func (o *JsonDB) GetClientByID(clientID string, hasQRCode bool) (model.ClientData, error) {
+func (o *JsonDB) GetClientByID(clientID string, qrCodeSettings model.QRCodeSettings) (model.ClientData, error) {
 	client := model.Client{}
 	clientData := model.ClientData{}
 
@@ -200,9 +204,17 @@ func (o *JsonDB) GetClientByID(clientID string, hasQRCode bool) (model.ClientDat
 	}
 
 	// generate client qrcode image in base64
-	if hasQRCode && client.PrivateKey != "" {
+	if qrCodeSettings.Enabled && client.PrivateKey != "" {
 		server, _ := o.GetServer()
 		globalSettings, _ := o.GetGlobalSettings()
+		client := client
+		client.UseServerDNS = qrCodeSettings.IncludeDNS
+		if !qrCodeSettings.IncludeMTU {
+			globalSettings.MTU = 0
+		}
+		if !qrCodeSettings.IncludeFwMark {
+			globalSettings.ForwardMark = ""
+		}
 
 		png, err := qrcode.Encode(util.BuildClientConfig(client, server, globalSettings), qrcode.Medium, 256)
 		if err == nil {
diff --git a/store/store.go b/store/store.go
index 98795b2..2dca8a7 100644
--- a/store/store.go
+++ b/store/store.go
@@ -10,7 +10,7 @@ type IStore interface {
 	GetGlobalSettings() (model.GlobalSetting, error)
 	GetServer() (model.Server, error)
 	GetClients(hasQRCode bool) ([]model.ClientData, error)
-	GetClientByID(clientID string, hasQRCode bool) (model.ClientData, error)
+	GetClientByID(clientID string, qrCode model.QRCodeSettings) (model.ClientData, error)
 	SaveClient(client model.Client) error
 	DeleteClient(clientID string) error
 	SaveServerInterface(serverInterface model.ServerInterface) error
diff --git a/templates/base.html b/templates/base.html
index 28f5e84..ff77df5 100644
--- a/templates/base.html
+++ b/templates/base.html
@@ -386,7 +386,7 @@
                     $("#modal_new_client").modal('hide');
                     toastr.success('Created new client successfully');
                     // Update the home page (clients page) after adding successfully
-                    if (window.location.pathname === "/") {
+                    if (window.location.pathname === "{{.basePath}}/") {
                         populateClient(resp.id);
                     }
                 },
diff --git a/templates/clients.html b/templates/clients.html
index 538782b..cdce8c0 100644
--- a/templates/clients.html
+++ b/templates/clients.html
@@ -68,7 +68,18 @@ Wireguard Clients
                     <span aria-hidden="true">&times;</span>
                 </button>
             </div>
-            <img id="qr_code" class="w-100" style="image-rendering: pixelated;" src="" alt="QR code" />
+            <div class="modal-body">
+                <input type="hidden" id="qr_client_id" name="qr_client_id">
+                <img id="qr_code" class="w-100" style="image-rendering: pixelated;" src="" alt="QR code" />
+                <div class="form-group">
+                    <div class="icheck-primary d-inline">
+                        <input type="checkbox" id="qr_include_fwmark" onchange="regenerateQRCode()">
+                        <label for="qr_include_fwmark">
+                            Include FwMark
+                        </label>
+                    </div>
+                </div>
+            </div>
         </div>
         <!-- /.modal-content -->
     </div>
@@ -387,6 +398,37 @@ Wireguard Clients
             });
         });
 
+        // regenerateQRCode function for regenerating QR Code adding/removing some parts of configuration because of compatibility issues with some clients
+        function regenerateQRCode() {
+            const client_id = $("#qr_client_id").val();
+            const QRCodeImg = $("#qr_code");
+            let include_fwmark = false;
+            if ($("#qr_include_fwmark").is(':checked')){
+                include_fwmark = true;
+            }
+            QRCodeImg.hide();
+            $.ajax({
+                cache: false,
+                method: 'GET',
+                url: '{{.basePath}}/api/client/' + client_id,
+                data: { 
+                    qrCodeIncludeFwMark: include_fwmark
+                },
+                dataType: 'json',
+                contentType: "application/json",
+                success: function (resp) {
+                    const client = resp.Client;
+
+                    $(".modal-title").text("Scan QR Code for " + client.name + " profile");
+                    QRCodeImg.attr('src', resp.QRCode).show();
+                },
+                error: function (jqXHR, exception) {
+                    const responseJson = jQuery.parseJSON(jqXHR.responseText);
+                    toastr.error(responseJson['message']);
+                }
+            });
+        }
+
         // submitEmailClient function for sending an email to the client with the configuration
         function submitEmailClient() {
             const client_id = $("#e_client_id").val();
@@ -467,7 +509,7 @@ Wireguard Clients
             const formId = $(form).attr('id');
             if (formId === "frm_edit_client") {
                 submitEditClient();
-            }else if (formId === "frm_email_client") {
+            } else if (formId === "frm_email_client") {
                 submitEmailClient();
             }
         }
@@ -500,31 +542,14 @@ Wireguard Clients
             let modal = $(this);
             const button = $(event.relatedTarget);
             const client_id = button.data('clientid');
-            const QRCodeImg = modal.find("#qr_code");
-            QRCodeImg.hide();
-            $.ajax({
-                cache: false,
-                method: 'GET',
-                url: '{{.basePath}}/api/client/' + client_id,
-                dataType: 'json',
-                contentType: "application/json",
-                success: function (resp) {
-                    const client = resp.Client;
 
-                    modal.find(".modal-title").text("Scan QR Code for " + client.name + " profile");
-                    QRCodeImg.attr('src', resp.QRCode).show();
-                },
-                error: function (jqXHR, exception) {
-                    const responseJson = jQuery.parseJSON(jqXHR.responseText);
-                    toastr.error(responseJson['message']);
-                }
-            });
+            modal.find("#qr_client_id").val(client_id);
+            regenerateQRCode();
         });
 
         $(document).ready(function () {
             $.validator.setDefaults({
                 submitHandler: function (form) {
-                    //submitEditClient();
                     submitHandler(form);
                 }
             });
@@ -577,6 +602,7 @@ Wireguard Clients
                     $(element).removeClass('is-invalid');
                 }
             });
+            // 
         });
     </script>
 {{end}}
diff --git a/templates/global_settings.html b/templates/global_settings.html
index 1c01438..3b0724e 100644
--- a/templates/global_settings.html
+++ b/templates/global_settings.html
@@ -172,7 +172,7 @@ Global Settings
         }
 
         function updateEndpointSuggestionIP() {
-            $.getJSON("/api/machine-ips", null, function(data) {
+            $.getJSON("{{.basePath}}/api/machine-ips", null, function(data) {
                 $("#ip_suggestion option").remove();
                 $.each(data, function(index, item) {
                     $("#ip_suggestion").append(
diff --git a/util/util.go b/util/util.go
index 8826ee6..5a3a5f1 100644
--- a/util/util.go
+++ b/util/util.go
@@ -70,7 +70,7 @@ func BuildClientConfig(client model.Client, server model.Server, setting model.G
 	}
 
 	forwardMark := ""
-	if setting.ForwardMark != "" && setting.ForwardMark != DefaultForwardMark {
+	if setting.ForwardMark != "" {
 		forwardMark = fmt.Sprintf("FwMark = %s\n", setting.ForwardMark)
 	}