improve readability

Author: NickOvt

lib/api/mailboxes.js

@@ -638,7 +638,7 @@ module.exports = (db, server, mailboxHandler) => {
 
             const updateResult = await updateMailbox(user, mailbox, updates);
 
-            if ('retention' in updates && updateResult && updateResult.changes && updateResult.changes.retention) {
+            if ('retention' in updates && updateResult?.changes?.retention) {
                 await taskHandler.ensure(
                     'mailbox-retention',
                     { user, mailbox },

lib/tools.js

@@ -212,7 +212,7 @@ async function getMailboxCounter(db, mailbox, type) {
 }
 
 function getMessageRetentionState(mailboxData, addedAt = Date.now()) {
-    const retention = Math.max(0, Number((mailboxData && mailboxData.retention) || 0) || 0);
+    const retention = mailboxData?.retention || 0;
 
     if (!retention) {
         return {