diff --git a/src/mail.js b/src/mail.js
index e8b9e6b17..8972272bb 100644
--- a/src/mail.js
+++ b/src/mail.js
@@ -312,7 +312,7 @@ async function checkSpf(domain, mailFqdn) {
     assert.strictEqual(typeof mailFqdn, 'string');
 
     const spf = {
-        domain: domain,
+        domain,
         name: '@',
         type: 'TXT',
         value: null,
@@ -350,7 +350,7 @@ async function checkMx(domain, mailFqdn) {
     assert.strictEqual(typeof mailFqdn, 'string');
 
     const mx = {
-        domain: domain,
+        domain,
         name: '@',
         type: 'MX',
         value: null,
@@ -395,7 +395,7 @@ function txtToDict(txt) {
 async function checkDmarc(domain) {
 
     const dmarc = {
-        domain: '_dmarc.' + domain,
+        domain: `_dmarc.${domain}`,
         name: '_dmarc',
         type: 'TXT',
         value: null,
@@ -923,17 +923,17 @@ async function upsertDnsRecords(domain, mailFqdn) {
     const publicKey = mailDomain.dkimKey.publicKey.split('\n').slice(1, -2).join(''); // remove header, footer and new lines
 
     // t=s limits the domainkey to this domain and not it's subdomains
-    const dkimRecord = { subdomain: `${mailDomain.dkimSelector}._domainkey`, domain: domain, type: 'TXT', values: [ `"v=DKIM1; t=s; p=${publicKey}"` ] };
+    const dkimRecord = { subdomain: `${mailDomain.dkimSelector}._domainkey`, domain, type: 'TXT', values: [ `"v=DKIM1; t=s; p=${publicKey}"` ] };
 
     const records = [];
     records.push(dkimRecord);
-    if (mailDomain.enabled) records.push({ subdomain: '', domain: domain, type: 'MX', values: [ '10 ' + mailFqdn + '.' ] });
+    if (mailDomain.enabled) records.push({ subdomain: '', domain, type: 'MX', values: [ '10 ' + mailFqdn + '.' ] });
 
     const txtRecords = await txtRecordsWithSpf(domain, mailFqdn);
-    if (txtRecords) records.push({ subdomain: '', domain: domain, type: 'TXT', values: txtRecords });
+    if (txtRecords) records.push({ subdomain: '', domain, type: 'TXT', values: txtRecords });
 
     const dmarcRecords = await dns.getDnsRecords('_dmarc', domain, 'TXT'); // only update dmarc if absent. this allows user to set email for reporting
-    if (dmarcRecords.length === 0) records.push({ subdomain: '_dmarc', domain: domain, type: 'TXT', values: [ '"v=DMARC1; p=reject; pct=100"' ] });
+    if (dmarcRecords.length === 0) records.push({ subdomain: '_dmarc', domain, type: 'TXT', values: [ '"v=DMARC1; p=reject; pct=100"' ] });
 
     debug(`upsertDnsRecords: will update ${domain} with ${JSON.stringify(records)}`);