diff --git a/tine20/Addressbook/js/ListEditDialog.js b/tine20/Addressbook/js/ListEditDialog.js
index 64941c36c2..75fa3a3ea2 100644
--- a/tine20/Addressbook/js/ListEditDialog.js
+++ b/tine20/Addressbook/js/ListEditDialog.js
@@ -97,16 +97,18 @@ Tine.Addressbook.ListEditDialog = Ext.extend(Tine.widgets.dialog.EditDialog, {
                                     if (editDialog?.mailingListPanel) {
                                         const checked = editDialog.mailingListPanel.isMailinglistCheckbox.checked;
                                         const field = editDialog.getForm().findField('email');
-                                        field.setVisible(checked);
-                                        field.validate();
+                                        field[checked ? 'show' : 'hide']();
                                         editDialog.doLayout();
+                                        field.validate();
                                     }
                                 },
                                 validator: function (value) {
-                                    if(!value) {
-                                        return false;
+                                    const editDialog = this.findParentBy((c) => {return c instanceof Tine.widgets.dialog.EditDialog})
+                                    if (editDialog?.mailingListPanel?.isMailinglistCheckbox?.checked) {
+                                        if (!value) return false;
+                                        return Tine.Tinebase.common.checkEmailDomain(value);
                                     }
-                                    return Tine.Tinebase.common.checkEmailDomain(value);
+                                    return true;
                                 },
                                 disabled: ! Tine.Tinebase.common.hasRight('manage_list_email_options', 'Addressbook'),
                             }], [new Tine.Tinebase.widgets.keyfield.ComboBox({
diff --git a/tine20/Addressbook/js/MailinglistPanel.js b/tine20/Addressbook/js/MailinglistPanel.js
index 6f1c82643a..b2098ea5dd 100644
--- a/tine20/Addressbook/js/MailinglistPanel.js
+++ b/tine20/Addressbook/js/MailinglistPanel.js
@@ -51,6 +51,7 @@ Tine.Addressbook.MailinglistPanel = Ext.extend(Ext.Panel, {
             maxLength: 128,
             disabled: ! Tine.Tinebase.common.hasRight('manage_list_email_options', 'Addressbook'),
             allowBlank: false,
+            hidden: true,
             checkState: function (editDialog, record) {
                 this.validate();
             },
diff --git a/tine20/Admin/js/GroupEditDialog.js b/tine20/Admin/js/GroupEditDialog.js
index b0d47da8cc..63bcba3f10 100644
--- a/tine20/Admin/js/GroupEditDialog.js
+++ b/tine20/Admin/js/GroupEditDialog.js
@@ -109,7 +109,7 @@ Tine.Admin.Groups.EditDialog = Ext.extend(Tine.widgets.dialog.EditDialog, {
                     disabled: this.record.get('visibility') === 'hidden'
                 }], [{
                     columnWidth: 0.5,
-                    xtype: 'textfield',
+                    xtype: 'mirrortextfield',
                     fieldLabel: this.app.i18n._('E-mail'),
                     name: 'email',
                     anchor: '100%',
@@ -117,10 +117,19 @@ Tine.Admin.Groups.EditDialog = Ext.extend(Tine.widgets.dialog.EditDialog, {
                     maxLength: 255,
                     allowBlank: true,
                     checkState: function (editDialog, field) {
-                            const checked = editDialog.record.data.xprops?.useAsMailinglist;
-                            field = editDialog.getForm().findField('email');
-                            field.setVisible(checked);
-                            editDialog.doLayout();
+                        const checked = editDialog.record.data.xprops?.useAsMailinglist;
+                        field = editDialog.getForm().findField('email');
+                        field[checked ? 'show' : 'hide']();
+                        editDialog.doLayout();
+                        field.validate();
+                    },
+                    validator: function (value) {
+                        const editDialog = this.findParentBy((c) => {return c instanceof Tine.widgets.dialog.EditDialog})
+                        if (editDialog?.record?.data?.xprops?.useAsMailinglist) {
+                            if (!value) return false;
+                            return Tine.Tinebase.common.checkEmailDomain(value);
+                        }
+                        return true;
                     },
                 }, {
                     columnWidth: 0.5,
@@ -151,10 +160,10 @@ Tine.Admin.Groups.EditDialog = Ext.extend(Tine.widgets.dialog.EditDialog, {
             Tine.Tinebase.registry.get('manageSmtpEmailUser') &&
             adb.featureEnabled('featureMailinglist')
         ) {
-            var mailingListPanel = new Tine.Addressbook.MailinglistPanel({
+            this.mailingListPanel = new Tine.Addressbook.MailinglistPanel({
                 editDialog: this
             });
-            tabpanelItems.push(mailingListPanel);
+            tabpanelItems.push(this.mailingListPanel);
         }
 
         if (this.app.featureEnabled('xpropsEditor')) {