diff --git a/worker/src/commom_api.ts b/worker/src/commom_api.ts
index c4bc939..bfe2fa7 100644
--- a/worker/src/commom_api.ts
+++ b/worker/src/commom_api.ts
@@ -20,6 +20,7 @@ api.get('/open_api/settings', async (c) => {
     ) || {};
     const smtpProxyConfig = smtpImapProxyConfig.smtp || {};
     const imapProxyConfig = smtpImapProxyConfig.imap || {};
+    const enableMailStates = utils.getBooleanValue(c.env.ENABLE_MAIL_FLAGS);
 
     return c.json({
         "title": c.env.TITLE,
@@ -39,7 +40,7 @@ api.get('/open_api/settings', async (c) => {
         "disableAnonymousUserCreateEmail": utils.getBooleanValue(c.env.DISABLE_ANONYMOUS_USER_CREATE_EMAIL),
         "disableCustomAddressName": utils.getBooleanValue(c.env.DISABLE_CUSTOM_ADDRESS_NAME),
         "enableUserDeleteEmail": utils.getBooleanValue(c.env.ENABLE_USER_DELETE_EMAIL),
-        "enableMailStates": utils.getBooleanValue(c.env.ENABLE_MAIL_FLAGS),
+        ...(enableMailStates ? { "enableMailStates": true } : {}),
         "enableAutoReply": utils.getBooleanValue(c.env.ENABLE_AUTO_REPLY),
         "enableIndexAbout": utils.getBooleanValue(c.env.ENABLE_INDEX_ABOUT),
         "copyright": c.env.COPYRIGHT,