diff --git a/config-default.json b/config-default.json
index 5ab5738..715c70c 100644
--- a/config-default.json
+++ b/config-default.json
@@ -4,5 +4,6 @@
     "port": 25,
     "disableWebhook": true
   },
-  "host": "disposable.dhc-app.com"
+  "host": "disposable.dhc-app.com",
+  "keywordBlackList": ["admin", "postmaster", "system", "webmaster", "administrator", "hostmaster", "service", "server", "root"]
 }
\ No newline at end of file
diff --git a/modules/config.js b/modules/config.js
new file mode 100644
index 0000000..9ba97ca
--- /dev/null
+++ b/modules/config.js
@@ -0,0 +1,21 @@
+/**
+ * Created by Hongcai Deng on 2015/12/28.
+ */
+
+'use strict';
+
+const path = require('path');
+const fs = require('fs');
+
+const defaultConfigJsonPath = path.join(__dirname, '..', 'config-default.json')
+const defaultConfigPath = path.join(__dirname, '..', 'config-default.js')
+
+let config = {};
+
+if (fs.existsSync(defaultConfigJsonPath)) {
+    config = require(defaultConfigJsonPath);
+} else {
+    config = require(defaultConfigPath);
+}
+
+module.exports = config;
\ No newline at end of file
diff --git a/modules/io.js b/modules/io.js
index 19078a8..2342404 100644
--- a/modules/io.js
+++ b/modules/io.js
@@ -4,11 +4,25 @@
 
 'use strict';
 
-let shortid = require('shortid');
-let mailin = require('./mailin');
+const shortid = require('shortid');
+const mailin = require('./mailin');
+const config = require('./config');
 
 let onlines = new Map();
 
+function checkShortIdMatchBlackList(id) {
+  const keywordBlackList = config.keywordBlackList;
+  if (keywordBlackList && keywordBlackList.length > 0) {
+    for (let i = 0; i < keywordBlackList.length; i++) {
+      const keyword = keywordBlackList[i];
+      if (id.includes(keyword)) {
+        return true;
+      }
+    }
+  } 
+  return false;
+}
+
 module.exports = function(io) {
   mailin.on('message', function(connection, data) {
     let to = data.headers.to.toLowerCase();
@@ -31,6 +45,10 @@ module.exports = function(io) {
     });
 
     socket.on('set shortid', function(id) {
+      if (checkShortIdMatchBlackList(id)) {
+        // skip set shortid if match keyword blacklist
+        return;
+      }
       onlines.delete(socket.shortid);
       socket.shortid = id;
       onlines.set(socket.shortid, socket);
diff --git a/modules/mailin.js b/modules/mailin.js
index 5b2fdf5..6802711 100644
--- a/modules/mailin.js
+++ b/modules/mailin.js
@@ -6,7 +6,7 @@
 
 let path = require('path');
 let mailin = require('mailin');
-let config = require(path.join(__dirname, '..', 'config-default.json'));
+let config = require('./config');
 
 mailin.start(config.mailin);