Hides the user invite button if there is no email server configured

src/Umbraco.Web.UI.Client/src/views/users/views/users/users.controller.js

@@ -37,12 +37,15 @@
             "selected": true
         };
 
-        vm.defaultButton = {
-            labelKey:"users_inviteUser",
-            handler: function() {
-                vm.setUsersViewState('inviteUser');
+        //don't set this if no email is configured
+        if (Umbraco.Sys.ServerVariables.umbracoSettings.emailServerConfigured) {
+          vm.defaultButton = {
+            labelKey: "users_inviteUser",
+            handler: function () {
+              vm.setUsersViewState('inviteUser');
             }
-        };
+          };  
+        }
 
         vm.subButtons = [
             {

src/Umbraco.Web/Editors/BackOfficeController.cs

@@ -5,6 +5,7 @@ using System.Globalization;
 using System.IO;
 using System.Linq;
 using System.Net;
+using System.Net.Configuration;
 using System.Net.Http;
 using System.Text;
 using System.Threading;
@@ -400,6 +401,7 @@ namespace Umbraco.Web.Editors
                             {"cssPath", IOHelper.ResolveUrl(SystemDirectories.Css).TrimEnd('/')},
                             {"allowPasswordReset", UmbracoConfig.For.UmbracoSettings().Security.AllowPasswordReset},
                             {"loginBackgroundImage",  UmbracoConfig.For.UmbracoSettings().Content.LoginBackgroundImage},
+                            {"emailServerConfigured", HasSmtpServerConfigured()},
                         }
                     },
                     {
@@ -447,6 +449,18 @@ namespace Umbraco.Web.Editors
             return JavaScript(result);
         }
 
+        private bool HasSmtpServerConfigured()
+        {
+            var config = WebConfigurationManager.OpenWebConfiguration(HttpContext.Request.ApplicationPath);
+            var settings = (MailSettingsSectionGroup)config.GetSectionGroup("system.net/mailSettings");
+            if (settings == null || settings.Smtp == null) return false;
+            if (settings.Smtp.SpecifiedPickupDirectory != null && string.IsNullOrEmpty(settings.Smtp.SpecifiedPickupDirectory.PickupDirectoryLocation) == false)
+                return true;
+            if (settings.Smtp.Network != null && string.IsNullOrEmpty(settings.Smtp.Network.Host) == false)
+                return true;
+            return false;
+        }
+
         [HttpPost]
         public ActionResult ExternalLogin(string provider, string redirectUrl = null)
         {