diff --git a/meshmail.js b/meshmail.js
index 5fbea5e9..c67a22e6 100644
--- a/meshmail.js
+++ b/meshmail.js
@@ -137,74 +137,103 @@ module.exports.CreateMeshMail = function (parent) {
 
     // Send account login mail / 2 factor token
     obj.sendAccountLoginMail = function (domain, email, token) {
-        var template = getTemplateEx('account-login', domain);
-        if ((template == null) || (template.htmlSubject == null) || (template.txtSubject == null) || (parent.certificates == null) || (parent.certificates.CommonName == null) || (parent.certificates.CommonName.indexOf('.') == -1)) return; // If the server name is not set, invitation not possible.
+        obj.checkEmail(email, function (checked) {
+            if (checked) {
+                parent.debug('email', "Sending login token to " + email);
 
-        // Set all the options.
-        var options = { email: email, servername: domain.title ? domain.title : 'MeshCentral', token: token };
+                var template = getTemplateEx('account-login', domain);
+                if ((template == null) || (template.htmlSubject == null) || (template.txtSubject == null) || (parent.certificates == null) || (parent.certificates.CommonName == null) || (parent.certificates.CommonName.indexOf('.') == -1)) return; // If the server name is not set, invitation not possible.
 
-        // Send the email
-        obj.pendingMails.push({ to: email, from: parent.config.smtp.from, subject: mailReplacements(template.htmlSubject, domain, options), text: mailReplacements(template.txt, domain, options), html: mailReplacements(template.html, domain, options) });
-        sendNextMail();
+                // Set all the options.
+                var options = { email: email, servername: domain.title ? domain.title : 'MeshCentral', token: token };
+
+                // Send the email
+                obj.pendingMails.push({ to: email, from: parent.config.smtp.from, subject: mailReplacements(template.htmlSubject, domain, options), text: mailReplacements(template.txt, domain, options), html: mailReplacements(template.html, domain, options) });
+                sendNextMail();
+            }
+        });
     };
 
     // Send account invitation mail
     obj.sendAccountInviteMail = function (domain, username, accountname, email, password) {
-        var template = getTemplateEx('account-invite', domain);
-        if ((template == null) || (template.htmlSubject == null) || (template.txtSubject == null) || (parent.certificates == null) || (parent.certificates.CommonName == null) || (parent.certificates.CommonName.indexOf('.') == -1)) return; // If the server name is not set, invitation not possible.
+        obj.checkEmail(email, function (checked) {
+            if (checked) {
+                parent.debug('email', "Sending account invitation to " + email);
 
-        // Set all the options.
-        var options = { username: username, accountname: accountname, email: email, servername: domain.title ? domain.title : 'MeshCentral', password: password };
+                var template = getTemplateEx('account-invite', domain);
+                if ((template == null) || (template.htmlSubject == null) || (template.txtSubject == null) || (parent.certificates == null) || (parent.certificates.CommonName == null) || (parent.certificates.CommonName.indexOf('.') == -1)) return; // If the server name is not set, invitation not possible.
 
-        // Send the email
-        obj.pendingMails.push({ to: email, from: parent.config.smtp.from, subject: mailReplacements(template.htmlSubject, domain, options), text: mailReplacements(template.txt, domain, options), html: mailReplacements(template.html, domain, options) });
-        sendNextMail();
+                // Set all the options.
+                var options = { username: username, accountname: accountname, email: email, servername: domain.title ? domain.title : 'MeshCentral', password: password };
+
+                // Send the email
+                obj.pendingMails.push({ to: email, from: parent.config.smtp.from, subject: mailReplacements(template.htmlSubject, domain, options), text: mailReplacements(template.txt, domain, options), html: mailReplacements(template.html, domain, options) });
+                sendNextMail();
+            }
+        });
     };
 
     // Send account check mail
     obj.sendAccountCheckMail = function (domain, username, email) {
-        var template = getTemplateEx('account-check', domain);
-        if ((template == null) || (template.htmlSubject == null) || (template.txtSubject == null) || (parent.certificates == null) || (parent.certificates.CommonName == null) || (parent.certificates.CommonName.indexOf('.') == -1)) return; // If the server name is not set, no reset possible.
+        obj.checkEmail(email, function (checked) {
+            if (checked) {
+                parent.debug('email', "Sending email verification to " + email);
 
-        // Set all the options.
-        var options = { username: username, email: email, servername: domain.title ? domain.title : 'MeshCentral' };
-        options.cookie = obj.parent.encodeCookie({ u: domain.id + '/' + username.toLowerCase(), e: email, a: 1 }, obj.mailCookieEncryptionKey);
+                var template = getTemplateEx('account-check', domain);
+                if ((template == null) || (template.htmlSubject == null) || (template.txtSubject == null) || (parent.certificates == null) || (parent.certificates.CommonName == null) || (parent.certificates.CommonName.indexOf('.') == -1)) return; // If the server name is not set, no reset possible.
 
-        // Send the email
-        obj.pendingMails.push({ to: email, from: parent.config.smtp.from, subject: mailReplacements(template.htmlSubject, domain, options), text: mailReplacements(template.txt, domain, options), html: mailReplacements(template.html, domain, options) });
-        sendNextMail();
+                // Set all the options.
+                var options = { username: username, email: email, servername: domain.title ? domain.title : 'MeshCentral' };
+                options.cookie = obj.parent.encodeCookie({ u: domain.id + '/' + username.toLowerCase(), e: email, a: 1 }, obj.mailCookieEncryptionKey);
+
+                // Send the email
+                obj.pendingMails.push({ to: email, from: parent.config.smtp.from, subject: mailReplacements(template.htmlSubject, domain, options), text: mailReplacements(template.txt, domain, options), html: mailReplacements(template.html, domain, options) });
+                sendNextMail();
+            }
+        });
     };
 
     // Send account reset mail
     obj.sendAccountResetMail = function (domain, username, email) {
-        var template = getTemplateEx('account-reset', domain);
-        if ((template == null) || (template.htmlSubject == null) || (template.txtSubject == null) || (parent.certificates == null) || (parent.certificates.CommonName == null) || (parent.certificates.CommonName.indexOf('.') == -1)) return; // If the server name is not set, don't validate the email address.
+        obj.checkEmail(email, function (checked) {
+            if (checked) {
+                parent.debug('email', "Sending account password reset to " + email);
 
-        // Set all the options.
-        var options = { username: username, email: email, servername: domain.title ? domain.title : 'MeshCentral' };
-        options.cookie = obj.parent.encodeCookie({ u: domain.id + '/' + username, e: email, a: 2 }, obj.mailCookieEncryptionKey);
+                var template = getTemplateEx('account-reset', domain);
+                if ((template == null) || (template.htmlSubject == null) || (template.txtSubject == null) || (parent.certificates == null) || (parent.certificates.CommonName == null) || (parent.certificates.CommonName.indexOf('.') == -1)) return; // If the server name is not set, don't validate the email address.
 
-        // Send the email
-        obj.pendingMails.push({ to: email, from: parent.config.smtp.from, subject: mailReplacements(template.htmlSubject, domain, options), text: mailReplacements(template.txt, domain, options), html: mailReplacements(template.html, domain, options) });
-        sendNextMail();
+                // Set all the options.
+                var options = { username: username, email: email, servername: domain.title ? domain.title : 'MeshCentral' };
+                options.cookie = obj.parent.encodeCookie({ u: domain.id + '/' + username, e: email, a: 2 }, obj.mailCookieEncryptionKey);
+
+                // Send the email
+                obj.pendingMails.push({ to: email, from: parent.config.smtp.from, subject: mailReplacements(template.htmlSubject, domain, options), text: mailReplacements(template.txt, domain, options), html: mailReplacements(template.html, domain, options) });
+                sendNextMail();
+            }
+        });
     };
 
     // Send agent invite mail
     obj.sendAgentInviteMail = function (domain, username, email, meshid, name, os, msg, flags, expirehours) {
-        var template = getTemplateEx('mesh-invite', domain);
-        if ((template == null) || (template.htmlSubject == null) || (template.txtSubject == null) || (parent.certificates == null) || (parent.certificates.CommonName == null) || (parent.certificates.CommonName.indexOf('.') == -1)) return; // If the server name is not set, don't validate the email address.
+        obj.checkEmail(email, function (checked) {
+            if (checked) {
+                parent.debug('email', "Sending agent install invitation to " + email);
+                var template = getTemplateEx('mesh-invite', domain);
+                if ((template == null) || (template.htmlSubject == null) || (template.txtSubject == null) || (parent.certificates == null) || (parent.certificates.CommonName == null) || (parent.certificates.CommonName.indexOf('.') == -1)) return; // If the server name is not set, don't validate the email address.
 
-        // Set all the template replacement options and generate the final email text (both in txt and html formats).
-        var options = { username: username, name: name, email: email, installflags: flags, msg: msg, meshid: meshid, meshidhex: meshid.split('/')[2], servername: domain.title ? domain.title : 'MeshCentral' };
-        options.windows = ((os == 0) || (os == 1)) ? 1 : 0;
-        options.linux = ((os == 0) || (os == 2)) ? 1 : 0;
-        options.osx = ((os == 0) || (os == 3)) ? 1 : 0;
-        options.link = (os == 4) ? 1 : 0;
-        options.linkurl = createInviteLink(domain, meshid, flags, expirehours);
+                // Set all the template replacement options and generate the final email text (both in txt and html formats).
+                var options = { username: username, name: name, email: email, installflags: flags, msg: msg, meshid: meshid, meshidhex: meshid.split('/')[2], servername: domain.title ? domain.title : 'MeshCentral' };
+                options.windows = ((os == 0) || (os == 1)) ? 1 : 0;
+                options.linux = ((os == 0) || (os == 2)) ? 1 : 0;
+                options.osx = ((os == 0) || (os == 3)) ? 1 : 0;
+                options.link = (os == 4) ? 1 : 0;
+                options.linkurl = createInviteLink(domain, meshid, flags, expirehours);
 
-        // Send the email
-        obj.pendingMails.push({ to: email, from: parent.config.smtp.from, subject: mailReplacements(template.htmlSubject, domain, options), text: mailReplacements(template.txt, domain, options), html: mailReplacements(template.html, domain, options) });
-        sendNextMail();
+                // Send the email
+                obj.pendingMails.push({ to: email, from: parent.config.smtp.from, subject: mailReplacements(template.htmlSubject, domain, options), text: mailReplacements(template.txt, domain, options), html: mailReplacements(template.html, domain, options) });
+                sendNextMail();
+            }
+        });
     };
 
     // Send out the next mail in the pending list
@@ -223,6 +252,7 @@ module.exports.CreateMeshMail = function (parent) {
                 sendNextMail(); // Send the next mail
             } else {
                 obj.retry++;
+                parent.debug('email', 'SMTP server failed: ' + JSON.stringify(err));
                 console.log('SMTP server failed: ' + JSON.stringify(err));
                 if (obj.retry < 6) { setTimeout(sendNextMail, 60000); } // Wait and try again
             }
@@ -238,6 +268,7 @@ module.exports.CreateMeshMail = function (parent) {
                 // Remove all non-object types from error to avoid a JSON stringify error.
                 var err2 = {};
                 for (var i in err) { if (typeof (err[i]) != 'object') { err2[i] = err[i]; } }
+                parent.debug('email', 'SMTP mail server ' + parent.config.smtp.host + ' failed: ' + JSON.stringify(err2));
                 console.log('SMTP mail server ' + parent.config.smtp.host + ' failed: ' + JSON.stringify(err2));
             }
         });
@@ -260,5 +291,18 @@ module.exports.CreateMeshMail = function (parent) {
         return '/agentinvite?c=' + parent.encodeCookie({ a: 4, mid: meshid, f: flags, expire: expirehours * 60 }, parent.invitationLinkEncryptionKey);
     }
 
+    // Check the email domain DNS MX record.
+    obj.approvedEmailDomains = {};
+    obj.checkEmail = function (email, func) {
+        var emailSplit = email.split('@');
+        if (emailSplit.length != 2) { func(false); return; }
+        if (obj.approvedEmailDomains[emailSplit[1]] === true) { func(true); return; }
+        require('dns').resolveMx(emailSplit[1], function (err, addresses) {
+            parent.debug('email', "checkEmail: " + email + ", " + (err == null));
+            if (err == null) { obj.approvedEmailDomains[emailSplit[1]] = true; }
+            func(err == null);
+        });
+    }
+
     return obj;
 };
\ No newline at end of file
diff --git a/package.json b/package.json
index ad0024ff..2bceaa40 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "meshcentral",
-  "version": "0.5.0-q",
+  "version": "0.5.0-r",
   "keywords": [
     "Remote Management",
     "Intel AMT",
diff --git a/translate/translate.json b/translate/translate.json
index c89bf6af..a20d28a0 100644
--- a/translate/translate.json
+++ b/translate/translate.json
@@ -3764,7 +3764,7 @@
       "pt": "Tem certeza de que deseja {0} o plug-in: {1}",
       "ru": "Вы уверенны, что {0} плагин: {1}",
       "xloc": [
-        "default.handlebars->27->1553"
+        "default.handlebars->27->1554"
       ],
       "zh-chs": "您確定要{0}插件嗎：{1}"
     },
@@ -4408,7 +4408,7 @@
       "pt": "Servidor CIRA",
       "ru": "CIRA Сервер",
       "xloc": [
-        "default.handlebars->27->1544"
+        "default.handlebars->27->1545"
       ],
       "zh-chs": "CIRA服務器"
     },
@@ -4425,7 +4425,7 @@
       "pt": "Comandos do servidor CIRA",
       "ru": "CIRA Сервер команды",
       "xloc": [
-        "default.handlebars->27->1545"
+        "default.handlebars->27->1546"
       ],
       "zh-chs": "CIRA服務器命令"
     },
@@ -4548,7 +4548,7 @@
       "pt": "Erro de chamada",
       "ru": "Ошибка вызова",
       "xloc": [
-        "default.handlebars->27->1554"
+        "default.handlebars->27->1555"
       ],
       "zh-chs": "通話錯誤"
     },
@@ -4966,7 +4966,7 @@
       "pt": "Verificando ...",
       "ru": "Проверка...",
       "xloc": [
-        "default.handlebars->27->1550",
+        "default.handlebars->27->1551",
         "default.handlebars->27->778"
       ],
       "zh-chs": "檢查..."
@@ -5824,7 +5824,7 @@
       "pt": "Encaminhador de conexão",
       "ru": "Ретранслятор подключения",
       "xloc": [
-        "default.handlebars->27->1543"
+        "default.handlebars->27->1544"
       ],
       "zh-chs": "連接繼電器"
     },
@@ -8723,6 +8723,12 @@
       ],
       "zh-chs": "郵件認證"
     },
+    {
+      "en": "Email Traffic",
+      "xloc": [
+        "default.handlebars->27->1538"
+      ]
+    },
     {
       "cs": "Ověření e-mailu",
       "de": "E-Mail-Verifizierung",
@@ -11386,7 +11392,7 @@
         "default.handlebars->27->1223",
         "default.handlebars->27->1229",
         "default.handlebars->27->1521",
-        "default.handlebars->27->1542"
+        "default.handlebars->27->1543"
       ],
       "zh-chs": "英特爾AMT"
     },
@@ -13186,7 +13192,7 @@
       "pt": "Menos",
       "ru": "Меньше",
       "xloc": [
-        "default.handlebars->27->1556"
+        "default.handlebars->27->1557"
       ],
       "zh-chs": "減"
     },
@@ -15252,7 +15258,7 @@
       "pt": "Mais",
       "ru": "Еще",
       "xloc": [
-        "default.handlebars->27->1555"
+        "default.handlebars->27->1556"
       ],
       "zh-chs": "更多"
     },
@@ -17996,7 +18002,7 @@
       "pt": "Ação do Plugin",
       "ru": "Действие плагина",
       "xloc": [
-        "default.handlebars->27->1552",
+        "default.handlebars->27->1553",
         "default.handlebars->27->159"
       ],
       "zh-chs": "插件動作"
@@ -20738,7 +20744,7 @@
       "pt": "Rastreamento de servidor",
       "ru": "Трассировка сервера",
       "xloc": [
-        "default.handlebars->27->1546"
+        "default.handlebars->27->1547"
       ],
       "zh-chs": "服務器跟踪"
     },
@@ -24177,7 +24183,7 @@
       "pt": "Atualizado",
       "ru": "Актуально",
       "xloc": [
-        "default.handlebars->27->1551"
+        "default.handlebars->27->1552"
       ],
       "zh-chs": "最新"
     },
@@ -25251,8 +25257,8 @@
       "pt": "Servidor web",
       "ru": "Веб-сервер",
       "xloc": [
-        "default.handlebars->27->1538",
-        "default.handlebars->27->1539"
+        "default.handlebars->27->1539",
+        "default.handlebars->27->1540"
       ],
       "zh-chs": "網絡服務器"
     },
@@ -25269,7 +25275,7 @@
       "pt": "Solicitações de servidor Web",
       "ru": "Запросы веб-сервера",
       "xloc": [
-        "default.handlebars->27->1540"
+        "default.handlebars->27->1541"
       ],
       "zh-chs": "Web服務器請求"
     },
@@ -25286,7 +25292,7 @@
       "pt": "Encaminhador de soquete da Web",
       "ru": "Ретранслятор Web Socket",
       "xloc": [
-        "default.handlebars->27->1541"
+        "default.handlebars->27->1542"
       ],
       "zh-chs": "Web套接字中繼"
     },
@@ -26123,7 +26129,7 @@
       "pt": "\\\\'",
       "ru": "\\\\'",
       "xloc": [
-        "default.handlebars->27->1549"
+        "default.handlebars->27->1550"
       ],
       "zh-chs": "\\\\'"
     },
@@ -26656,7 +26662,7 @@
       "pt": "servertrace.csv",
       "ru": "servertrace.csv",
       "xloc": [
-        "default.handlebars->27->1548"
+        "default.handlebars->27->1549"
       ],
       "zh-chs": "servertrace.csv"
     },
@@ -26722,7 +26728,7 @@
       "pt": "hora, fonte, mensagem",
       "ru": "time, source, message",
       "xloc": [
-        "default.handlebars->27->1547"
+        "default.handlebars->27->1548"
       ],
       "zh-chs": "時間，來源，訊息"
     },
diff --git a/views/default.handlebars b/views/default.handlebars
index 0795560a..87000a2d 100644
--- a/views/default.handlebars
+++ b/views/default.handlebars
@@ -10805,6 +10805,7 @@
             x += '<div><label><input type=checkbox id=p41c14 ' + ((serverTraceSources.indexOf('agentupdate') >= 0) ? 'checked' : '') + '>' + "MeshAgent update" + '</label></div>';
             x += '<div><label><input type=checkbox id=p41c16 ' + ((serverTraceSources.indexOf('cert') >= 0) ? 'checked' : '') + '>' + "Server Certificate" + '</label></div>';
             x += '<div><label><input type=checkbox id=p41c17 ' + ((serverTraceSources.indexOf('db') >= 0) ? 'checked' : '') + '>' + "Server Database" + '</label></div>';
+            x += '<div><label><input type=checkbox id=p41c18 ' + ((serverTraceSources.indexOf('email') >= 0) ? 'checked' : '') + '>' + "Email Traffic" + '</label></div>';
             x += '<div style="width:100%;border-bottom:1px solid gray;margin-bottom:5px;margin-top:5px"><b>' + "Web Server" + '</b></div>';
             x += '<div><label><input type=checkbox id=p41c5 ' + ((serverTraceSources.indexOf('web') >= 0) ? 'checked' : '') + '>' + "Web Server" + '</label></div>';
             x += '<div><label><input type=checkbox id=p41c6 ' + ((serverTraceSources.indexOf('webrequest') >= 0) ? 'checked' : '') + '>' + "Web Server Requests" + '</label></div>';
@@ -10821,8 +10822,8 @@
         }
 
         function setServerTracingEx(b) {
-            var sources = [], allsources = ['cookie', 'dispatch', 'main', 'peer', 'web', 'webrequest', 'relay', 'webrelaydata', 'webrelay', 'mps', 'mpscmd', 'swarm', 'swarmcmd', 'agentupdate', 'agent', 'cert', 'db'];
-            if (b == 1) { for (var i = 1; i < 18; i++) { try { if (Q('p41c' + i).checked) { sources.push(allsources[i - 1]); } } catch (ex) { } } }
+            var sources = [], allsources = ['cookie', 'dispatch', 'main', 'peer', 'web', 'webrequest', 'relay', 'webrelaydata', 'webrelay', 'mps', 'mpscmd', 'swarm', 'swarmcmd', 'agentupdate', 'agent', 'cert', 'db', 'email'];
+            if (b == 1) { for (var i = 1; i < 19; i++) { try { if (Q('p41c' + i).checked) { sources.push(allsources[i - 1]); } } catch (ex) { } } }
             meshserver.send({ action: 'traceinfo', traceSources: sources });
         }